Method for expansion of a population of cells with IL2R beta/common gamma chain antibodies

ABSTRACT

Anti-CD122 and/or γc antibodies and fragments thereof are disclosed. Also disclosed are compositions comprising such antibodies and fragments, and uses and methods using the same.

RELATED APPLICATIONS

This application is a 35 U.S.C. § 371 national phase application ofInternational Application Serial No. PCT/EP2016/068780, filed Aug. 5,2016, entitled “IL2RBETA/COMMON GAMMA CHAIN ANTIBODIES”, which claimspriority to SG 10201506227V, filed Aug. 6, 2015, both of which areincorporated herein by reference in their entirety.

REFERENCE TO A “SEQUENCE LISTING”

Incorporated by reference herein in its entirety is the Sequence Listingentitled “PCT_EP21016_068780 Sequence_Listing.txt”, created Jan. 30,2018, size of 177 kilobytes.

FIELD OF THE INVENTION

The present invention relates to antibodies that bind to interleukin 2receptor β (IL-2Rβ; CD122) and common γ chain (γc; CD132).

BACKGROUND TO THE INVENTION

IL-2 is an essential cytokine that plays a central role in maintaining Tcell homeostasis and mediating proper immune responses. Its high potencyas an immune stimulator has led to clinical uses to treat a range ofconditions, including cancers and AIDS; it is also widely used as anadjuvant for vaccination to stimulate activation and proliferation ofvarious effector cells.

However, the high dose of IL-2 that is required for effective treatmentof certain diseases is highly toxic. Major adverse effects of suchtherapy include vascular leak syndrome (VLS), which results inaccumulation of the intravascular fluid in organs such as lung and liverwith subsequent pulmonary edema and liver damage. There is no treatmentfor VLS except withdrawing the therapy.

IL-2 exerts its pleiotropic functions by binding to differentcombinations of receptor components expressed on different cell types:the alpha chain (IL-2Rα, also known as CD25), the beta chain (IL-2Rβ, orCD122), and the common cytokine receptor gamma chain (IL-2Rγ, γc, orCD132).

Isolated IL-2Rα has been termed the “low affinity” IL-2 receptor(binding affinity K_(D)˜10 nM) and is not involved in signaltransduction. A complex of IL-2Rβ and γc binds IL-2 with intermediateaffinity (K_(D)˜1 nM), although IL-2Rβ alone has very low affinity(K_(D)˜100 nM) and γc alone has virtually no detectable binding affinityfor IL-2. A complex with all three subunits, IL-2Rα, IL-2Rβ, and γc,binds IL-2 with high affinity (K_(D)˜10 pM).

Heterodimerization of IL-2Rβ and γc is necessary and sufficient foreffective signal transduction through the interaction of theircytoplasmic domains and subsequent kinase activation of multiplesignaling pathways; IL-2Rα plays no role in signal transduction.

High-affinity α-β-γc IL-2Rs are typically found on CD4+T regulatorycells (Tregs) as well as recently-activated T cells.Intermediate-affinity β-γc IL-2Rs are present at a low level on naïveCD8+ cells, but are prominent on antigen-experienced (memory) andmemory-phenotype (MP) CD8+ T cells as well as natural killer (NK) cells.Both MPCD8+ T cells and NK cells express very high levels of IL-2Rβ andreadily respond to IL-2.

Previous studies have indicated that VLS is caused by the release ofproinflammatory cytokines from IL-2-activated NK cells. However, arecent study suggested that IL-2-induced pulmonary edema may result fromdirect binding of IL-2 to lung endothelial cells, which expressfunctional high affinity α-β-γc IL-2Rs. This was evidenced by theobservation that interaction of IL-2 with lung endothelial cells wasabrogated by blocking anti-IL-2Rα monoclonal antibody (mAb), inIL-2Rα-deficient host mice, or by the use of an IL-2/anti-IL-2 mAb(IL-2/mAb) complex in which the antibody prevents IL-2/IL-2Rαinteraction, thus preventing VLS.

SUMMARY OF THE INVENTION

The present invention is concerned with antibodies, or antigen bindingfragments, that bind to CD122 and/or common γ chain (γc). Heavy andlight chain polypeptides for CD122 and common γ chain (γc) bindingantibodies are also disclosed. The antibodies, antigen binding fragmentsand polypeptides may be provided in isolated and/or purified form andmay be formulated into compositions suitable for use in research,therapy and diagnosis.

In a first aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding toCD122 and common γ chain (γc).

In some embodiments, the antibody or antigen binding fragment is abispecific antibody or a bispecific antigen binding fragment.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding toCD122, comprising the amino acid sequences i) to vi):

i) LC-CDR1: (SEQ ID NO: 85) TGTSSDIGX₁YDFX₂S (SEQ ID NO: 6) RAGQAISSWLA;(SEQ ID NO: 10) QASQDIGNYLN; or (SEQ ID NO: 14) TRSSGSIASNYVQ; ii)LC-CDR2: (SEQ ID NO: 86) DX₃NNRX₄S; (SEQ ID NO: 7) KASNLES; (SEQ ID NO:11) DASNLET; or (SEQ ID NO: 15) DDNQRPT; iii) LC-CDR3: (SEQ ID NO: 87)SAYTSSDTX₅V; (SEQ ID NO: 8) QQYQSYPYT; (SEQ ID NO: 12) LQLYDYPLT; or(SEQ ID NO: 16) QSSHSTAVV; iv) HC-CDR1: (SEQ ID NO: 88) NYYX₆H; (SEQ IDNO: 40) TYAMH; (SEQ ID NO: 44) SYAMS; or (SEQ ID NO: 48) GYYWS; v)HC-CDR2: (SEQ ID NO: 37) AIMPSRGGTSYPQKFQG; (SEQ ID NO: 41)WINTGNGNTKYSQNFQG; (SEQ ID NO: 45) AISGSGGSTYYADSVKG; or (SEQ ID NO: 49)EINHSGSTNYNPSLKS; vi) HC-CDR3: (SEQ ID NO: 89) GEYYYDSSGYYX₇; (SEQ IDNO: 42) DLGQLERLYFW; (SEQ ID NO: 46) DLGDY; or (SEQ ID NO: 50) SSSGDAFD;

-   -   or a variant thereof in which one or two or three amino acids in        one or more of the sequences i) to vi) are replaced with another        amino acid, wherein X₁=H or D; X₂=V or I; X₃=I, N or F; X₄=P or        A; X₅=L or V; X₆=M or I; and X₇=Y or N.

In some embodiments, LC-CDR1 is one of TGTSSDIGHYDFVS (SEQ ID NO:2),TGTSSDIGDYDFVS (SEQ ID NO:18), TGTSSDIGHYDFIS (SEQ ID NO:25),RAGQAISSWLA (SEQ ID NO:6), QASQDIGNYLN (SEQ ID NO:10), or TRSSGSIASNYVQ(SEQ ID NO:14).

In some embodiments, LC-CDR2 is one of DINNRPS (SEQ ID NO:3), DNNNRPS(SEQ ID NO:20), DFNNRPS (SEQ ID NO:26), DINNRAS (SEQ ID NO:32), KASNLES(SEQ ID NO:7), DASNLET (SEQ ID NO:11), or DDNQRPT (SEQ ID NO:15).

In some embodiments, LC-CDR3 is one of SAYTSSDTLV (SEQ ID NO:4),SAYTSSDTW (SEQ ID NO:22), QYQSYPYT (SEQ ID NO:8), LQLYDYPLT (SEQ IDNO:12), or QSSHSTAW (SEQ ID NO:16).

In some embodiments, HC-CDR1 is one of NYYMH (SEQ ID NO:36), NYYIH (SEQID NO:54), TYAMH (SEQ ID NO:40), SYAMS (SEQ ID NO:44), or GYYWS (SEQ IDNO:48).

In some embodiments, HC-CDR2 is one of AIMPSRGGTSYPQKFQG (SEQ ID NO:37),WINTGNGNTKYSQNFQG (SEQ ID NO:41), AISGSGGSTYYADSVKG (SEQ ID NO:45), orEINHSGSTNYNPSLKS (SEQ ID NO:49).

In some embodiments, HC-CDR3 is one of GEYYYDSSGYYY (SEQ ID NO:38),GEYYYDSSGYYN (SEQ ID NO:52), DLGQLERLYFW (SEQ ID NO:42), DLGDY (SEQ IDNO:46), or SSSGDAFD (SEQ ID NO:50).

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS LC-CDR2: (SEQ ID NO: 3) DINNRPSLC-CDR3: (SEQ ID NO: 4) SAYTSSDTLV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 18) TGTSSDIGDYDFVS LC-CDR2: (SEQ ID NO: 3) DINNRPSLC-CDR3: (SEQ ID NO: 4) SAYTSSDTLV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS LC-CDR2: (SEQ ID NO: 20) DNNNRPSLC-CDR3: (SEQ ID NO: 4) SAYTSSDTLV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS LC-CDR2: (SEQ ID NO: 3) DINNRPSLC-CDR3: (SEQ ID NO: 22) SAYTSSDTVV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 25) TGTSSDIGHYDFIS LC-CDR2: (SEQ ID NO: 26) DFNNRPSLC-CDR3: (SEQ ID NO: 4) SAYTSSDTLV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS LC-CDR2: (SEQ ID NO: 20) DNNNRPSLC-CDR3: (SEQ ID NO: 22) SAYTSSDTVV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS LC-CDR2: (SEQ ID NO: 32) DNNNRASLC-CDR3: (SEQ ID NO: 22) SAYTSSDTVV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 18) TGTSSDIGDYDFVS LC-CDR2: (SEQ ID NO: 3) DINNRPSLC-CDR3: (SEQ ID NO: 22) SAYTSSDTVV

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 6) RAGQAISSWLA LC-CDR2: (SEQ ID NO: 7) KASNLESLC-CDR3: (SEQ ID NO: 8) QQYQSYPYT.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 10) QASQDIGNYLN LC-CDR2: (SEQ ID NO: 11) DASNLETLC-CDR3: (SEQ ID NO: 12) LQLYDYPLT

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 14) TRSSGSIASNYVQ LC-CDR2: (SEQ ID NO: 15) DDNQRPTLC-CDR3: (SEQ ID NO: 16) QSSHSTAVV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 36) NYYMH HC-CDR2: (SEQ ID NO: 37)AIMPSRGGTSYPQKFQG HC-CDR3: (SEQ ID NO: 38) GEYYYDSSGYYY.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 36) NYYMH HC-CDR2: (SEQ ID NO: 37)AIMPSRGGTSYPQKFQG HC-CDR3: (SEQ ID NO: 38) GEYYYDSSGYYY.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 36) NYYMH HC-CDR2: (SEQ ID NO: 37)AIMPSRGGTSYPQKFQG HC-CDR3: (SEQ ID NO: 52) GEYYYDSSGYYN.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 54) NYYIH HC-CDR2: (SEQ ID NO: 37)AIMPSRGGTSYPQKFQG HC-CDR3: (SEQ ID NO: 38) GEYYYDSSGYYY.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 40) TYAMH HC-CDR2: (SEQ ID NO: 41)WINTGNGNTKYSQNFQG HC-CDR3: (SEQ ID NO: 42) DLGQLERLYFW.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 44) SYAMS HC-CDR2: (SEQ ID NO: 45)AISGSGGSTYYADSVKG HC-CDR3: (SEQ ID NO: 46) DLGDY.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 48) GYYWS HC-CDR2: (SEQ ID NO: 49) EINHSGSTNYNPSLKSHC-CDR3: (SEQ ID NO: 50) SSSGDAFD.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding toCD122, comprising a light chain and a heavy chain variable regionsequence, wherein:

-   -   the light chain comprises a LC-CDR1, LC-CDR2, LC-CDR3, having at        least 85% overall sequence identity to LC-CDR1: one of        TGTSSDIGX₁YDFX₂S (SEQ ID NO:85), RAGQAISSWLA (SEQ ID NO:6);        QASQDIGNYLN (SEQ ID NO:10); or TRSSGSIASNYVQ (SEQ ID NO:14);        LC-CDR2: one of DX₃NNRX₄S (SEQ ID NO:86); KASNLES (SEQ ID NO:7);        DASNLET (SEQ ID NO:11); or DDNQRPT (SEQ ID NO:15); LC-CDR3: one        of SAYTSSDTX₅V (SEQ ID NO:87); QQYQSYPYT (SEQ ID NO:8);        LQLYDYPLT (SEQ ID NO:12); or QSSHSTAW (SEQ ID NO:16); and    -   the heavy chain comprises a HC-CDR1, HC-CDR2, HC-CDR3, having at        least 85% overall sequence identity to HC-CDR1: one of NYYX₆H        (SEQ ID NO:88); TYAMH (SEQ ID NO:40); SYAMS (SEQ ID NO:44); or        GYYWS (SEQ ID NO:48); HC-CDR2: one of AIMPSRGGTSYPQKFQG (SEQ ID        NO:37); WINTGNGNTKYSQNFQG (SEQ ID NO:41); AISGSGGSTYYADSVKG (SEQ        ID NO:45); or EINHSGSTNYNPSLKS (SEQ ID NO:49); HC-CDR3: one of        GEYYYDSSGYYX₇ (SEQ ID NO:89); DLGQLERLYFW (SEQ ID NO:42); DLGDY        (SEQ ID NO:46); or SSSGDAFD (SEQ ID NO:50);    -   wherein X₁=H or D; X₂=V or I; X₃=I, N or F; X₄=P or A; X₅=L or        V; X₆=M or I; and X₇=Y or N.

In some embodiments the degree of sequence identity may be one of 86%,87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or100%.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding toCD122, comprising a light chain and a heavy chain variable regionsequence, wherein:

-   -   the light chain sequence has at least 85% sequence identity to        the light chain sequence of one of SEQ ID NOs:1, 17, 19, 21, 23,        24, 27, 28, 29, 30, 31, 33, 34, 148, 149, 5, 9, or 13 (FIG. 1),        and;    -   the heavy chain sequence has at least 85% sequence identity to        the heavy chain sequence of one of SEQ ID NOs:35, 51, 53, 55,        56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 150, 151, 39, 43, or        47 (FIG. 2).

In some embodiments the degree of sequence identity may be one of 86%,87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or100%.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding toCD122, which is a bispecific antibody or a bispecific antigen bindingfragment comprising (i) an antigen binding fragment according to thepresent invention, and (ii) an antigen binding fragment capable ofbinding to common γ chain (γc).

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding tocommon γ chain (γc), comprising the amino acid sequences i) to vi):

i) LC-CDR1: (SEQ ID NO: 68) RSSQSLLHSNGYNYLD; or (SEQ ID NO: 72)SGDALPKQFAF; ii) LC-CDR2: (SEQ ID NO: 69) LGSNRDS; or (SEQ ID NO: 73)KDTERPS; iii) LC-CDR3: (SEQ ID NO: 70) MQGTHWPWT; or (SEQ ID NO: 74)QSPDSSGTVEV; iv) HC-CDR1: (SEQ ID NO: 48) GYYWS; or (SEQ ID NO: 79)SSSYYWG; v) HC-CDR2: (SEQ ID NO: 90) EINHX₈GSTNYNPSLKS; or(SEQ ID NO: 80) SIYYSGSTYYNPSLK; vi) HC-CDR3: (SEQ ID NO: 77)SPGGYSGGYFQH; or (SEQ ID NO: 81) DILTGYALDY;

-   -   or a variant thereof in which one or two or three amino acids in        one or more of the sequences i) to vi) are replaced with another        amino acid, wherein X₈=S or F.

In some embodiments, LC-CDR1 is RSSQSLLHSNGYNYLD (SEQ ID NO:68) orSGDALPKQFAF (SEQ ID NO:72).

In some embodiments, LC-CDR2 is LGSNRDS (SEQ ID NO:69) or KDTERPS (SEQID NO:73).

In some embodiments, LC-CDR3 is MQGTHWPWT (SEQ ID NO:70) or QSPDSSGTVEV(SEQ ID NO:74).

In some embodiments, HC-CDR1 is GYYWS (SEQ ID NO:48) or SSSYYWG (SEQ IDNO:79).

In some embodiments, HC-CDR2 is one of EINHSGSTNYNPSLKS (SEQ ID NO:49),EINHFGSTNYNPSLKS (SEQ ID NO:83), or SIYYSGSTYYNPSLK (SEQ ID NO:80).

In some embodiments, HC-CDR3 is SPGGYSGGYFQH (SEQ ID NO:77) orDILTGYALDY (SEQ ID NO:81).

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 68) RSSQSLLHSNGYNYLD LC-CDR2: (SEQ ID NO: 69)LGSNRDS LC-CDR3: (SEQ ID NO: 70) MQGTHWPWT.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated light chainpolypeptide, having at least one light chain variable regionincorporating the following CDRs:

LC-CDR1: (SEQ ID NO: 72) SGDALPKQFAF LC-CDR2: (SEQ ID NO: 73) KDTERPSLC-CDR3: (SEQ ID NO: 74) QSPDSSGTVEV.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 48) GYYWS HC-CDR2: (SEQ ID NO: 49) EINHSGSTNYNPSLKSHC-CDR3: (SEQ ID NO: 77) SPGGYSGGYFQH.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 48) GYYWS HC-CDR2: (SEQ ID NO: 83) EINHFGSTNYNPSLKSHC-CDR3: (SEQ ID NO: 77) SPGGYSGGYFQH.

In some embodiments in accordance with various aspects, the presentinvention provides an antibody or fragment, or an isolated heavy chainpolypeptide, having at least one heavy chain variable regionincorporating the following CDRs:

HC-CDR1: (SEQ ID NO: 79) SSSYYWG HC-CDR2: (SEQ ID NO: 80)SIYYSGSTYYNPSLK HC-CDR3: (SEQ ID NO: 81) DILTGYALDY.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated which is capable of binding tocommon γ chain (γc), comprising a light chain and a heavy chain variableregion sequence, wherein:

-   -   the light chain comprises a LC-CDR1, LC-CDR2, LC-CDR3, having at        least 85% overall sequence identity to LC-CDR1: RSSQSLLHSNGYNYLD        (SEQ ID NO:68) or SGDALPKQFAF (SEQ ID NO:72); LC-CDR2: LGSNRDS        (SEQ ID NO:69) or KDTERPS (SEQ ID NO:73); LC-CDR3: MQGTHWPWT        (SEQ ID NO:70) or QSPDSSGTVEV (SEQ ID NO:74); and    -   the heavy chain comprises a HC-CDR1, HC-CDR2, HC-CDR3, having at        least 85% overall sequence identity to HC-CDR1: GYYWS (SEQ ID        NO:48) or SSSYYWG (SEQ ID NO:79); HC-CDR2: EINHX₈GSTNYNPSLKS        (SEQ ID NO:90) or SIYYSGSTYYNPSLK (SEQ ID NO:80); HC-CDR3:        SPGGYSGGYFQH (SEQ ID NO:77) or DILTGYALDY (SEQ ID NO:81);    -   wherein X₈=S or F.

In some embodiments the degree of sequence identity may be one of 86%,87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or100%.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding tocommon γ chain (γc), comprising a light chain and a heavy chain variableregion sequence, wherein:

-   -   the light chain sequence has at least 85% sequence identity to        the light chain sequence of one of SEQ ID NOs:67, 152, 71, or 75        (FIG. 3), and;    -   the heavy chain sequence has at least 85% sequence identity to        the heavy chain sequence of one of SEQ ID NOs:76, 153, 78, 82 or        84 (FIG. 4).

In some embodiments the degree of sequence identity may be one of 86%,87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or100%.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding tocommon γ chain (γc), which is a bispecific antibody or a bispecificantigen binding fragment comprising (i) an antigen binding fragmentaccording to the present invention, and (ii) an antigen binding fragmentcapable of binding to CD122.

In another aspect, the present invention provides an antibody or antigenbinding fragment, optionally isolated, which is capable of binding tocommon γ chain (γc) and CD122, comprising:

-   -   (i) a γc-binding antigen binding fragment according to the        present invention; and    -   (ii) a CD122-binding antigen binding fragment according to the        present invention.

In another aspect, the present invention provides an in vitro complex,optionally isolated, comprising an antibody or antigen binding fragment,according to the present invention bound to CD122, optionally whereinthe antibody or antigen binding fragment is bound to common γ chain(γc).

In another aspect, the present invention provides an in vitro complex,optionally isolated, comprising an antibody or antigen binding fragment,according to the present invention bound to common γ chain (γc),optionally wherein the antibody or antigen binding fragment is bound toCD122.

In some embodiments, the antibody or antigen binding fragment accordingto the present invention is conjugated to a drug moiety or a detectablemoiety.

In another aspect, the present invention provides a chimeric antigenreceptor (CAR) comprising an antigen binding fragment, optionally abispecific antigen binding fragment, according to the present invention.

In another aspect, the present invention provides a cell comprising achimeric antigen receptor (CAR) according to the present invention.

In another aspect, the present invention provides a compositioncomprising the antibody, antigen binding fragment, conjugate, chimericantigen receptor (CAR) or cell according to the present invention, andat least one pharmaceutically-acceptable carrier, excipient, adjuvant ordiluent.

In another aspect, the present invention provides an isolated nucleicacid encoding the antibody, antigen binding fragment, conjugate, orchimeric antigen receptor (CAR) according to the present invention. Thenucleic acid may have a sequence of one of SEQ ID NOs 130, 131, 132,133, 134, 135, 136, 137, 138, 19, 140, 141, 142, 143, 144, 145, 146 or147 (FIGS. 17 and 18), or a coding sequence which is degenerate as aresult of the genetic code, or may have a nucleotide sequence having atleast 70% identity thereto, optionally one of 75%, 80%, 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%.

In another aspect, the present invention provides a vector comprisingthe nucleic acid according to the present invention.

In another aspect, the present invention provides a host cell comprisingthe vector according to the present invention. For example, the hostcell may be eukaryotic, or mammalian, e.g. Chinese Hamster Ovary (CHO),or human or may be a prokaryotic cell, e.g. E. coli.

In another aspect, the present invention provides a method for making anantibody, antigen binding fragment, conjugate, or chimeric antigenreceptor (CAR) according to the present invention, comprising culturingthe host cell according to the present invention under conditionssuitable for the expression of a vector encoding the antibody, antigenbinding fragment, conjugate or CAR, and recovering the antibody, antigenbinding fragment, polypeptide, conjugate or CAR.

In another aspect, the present invention provides an antibody, antigenbinding fragment, polypeptide, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention for use intherapy, or in a method of medical treatment.

In another aspect, the present invention provides an antibody, antigenbinding fragment, polypeptide, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention for use inthe treatment of cancer.

In another aspect, the present invention provides an antibody, antigenbinding fragment, polypeptide, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention for use inthe treatment of an infectious disease.

In another aspect, the present invention provides the use of anantibody, antigen binding fragment, polypeptide, conjugate, chimericantigen receptor (CAR), cell or composition according to the presentinvention in the manufacture of a medicament for use in the treatment ofcancer.

In another aspect, the present invention provides the use of anantibody, antigen binding fragment, polypeptide, conjugate, chimericantigen receptor (CAR), cell or composition according to the presentinvention in the manufacture of a medicament for use in the treatment ofan infectious disease.

In another aspect, the present invention provides a method of treatingcancer comprising administering an antibody, antigen binding fragment,polypeptide, conjugate, chimeric antigen receptor (CAR), cell orcomposition according to the present invention to a patient sufferingfrom a cancer.

In another aspect, the present invention provides a method of treatingan infectious disease comprising administering an antibody, antigenbinding fragment, polypeptide, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention to apatient suffering from an infectious disease.

In another aspect, the present invention provides a method comprisingcontacting, preferably in vitro, a sample containing, or suspected tocontain, CD122 and/or common γ chain (γc) with an antibody, antigenbinding fragment, polypeptide, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention anddetecting the formation of a complex of the antibody, antigen bindingfragment, conjugate, CAR or cell with CD122 and/or γc.

In another aspect, the present invention provides a method of diagnosinga disease or condition in a subject, the method comprising contacting,preferably in vitro, a sample from the subject with an antibody, antigenbinding fragment, conjugate, chimeric antigen receptor (CAR), cell orcomposition according to the present invention and detecting theformation of a complex of the antibody, antigen binding fragment,conjugate, CAR or cell with CD122 and/or common γ chain (γc).

In another aspect, the present invention provides a method of selectingor stratifying a subject for treatment with an CD122 and/or common γchain (γc)-targeted agent, the method comprising contacting, preferablyin vitro, a sample from the subject with an antibody, antigen bindingfragment, conjugate, chimeric antigen receptor (CAR), cell orcomposition according to the present invention and detecting theformation of a complex of the antibody, antigen binding fragment,conjugate, CAR or cell with CD122 and/or γc.

In another aspect, the present invention provides the use of anantibody, antigen binding fragment, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention for thedetection of CD122 and/or common γ chain (γc) in vitro or in vivo.

In another aspect, the present invention provides the use of anantibody, antigen binding fragment, conjugate, chimeric antigen receptor(CAR), cell or composition according to the present invention as an invitro or in vivo diagnostic or prognostic agent.

In another aspect, the present invention provides a method for expandinga population of T cells and/or NK cells, wherein T cells and/or NK cellsare contacted in vitro, in vivo or ex vivo with an antibody, antigenbinding fragment, conjugate, chimeric antigen receptor (CAR), cell orcomposition according to the present invention.

In another aspect, the present invention provides a method of treatingan infectious disease or a cancer in a subject, the method comprisingculturing T cells and/or NK cells obtained from a blood sample from asubject in the presence of an antibody, antigen binding fragment,conjugate, chimeric antigen receptor (CAR), cell or compositionaccording to the present invention so as to expand a T cell and/or NKcell population, collecting expanded T cells and/or NK cells, andadministering the expanded T cells and/or NK cells to a subject in needof treatment.

In another aspect, the present invention provides a method of treatingan infectious disease or a cancer in a subject, the method comprisingadministering an antibody, antigen binding fragment, conjugate, chimericantigen receptor (CAR), cell or composition according to the presentinvention to the subject so as to expand a T cell and/or NK cellpopulation.

The following numbered paragraphs (paras) describe further aspects ofthe present invention:

1. An isolated IL-2R bispecific antigen binding protein comprising:

(i) a first IL-2Rβ binding polypeptide:

(a) a binding unit VL1 consisting of an amino acid sequence of SEQ IDNO:1, 5, 9, or 13, or a variant thereof which contains at least oneamino acid substitution, insertion or deletion in the binding unit VL1;

(b) a binding unit VH1 consisting of an amino acid sequence of SEQ IDNO:35, 39, 43, or 47, or a variant thereof which contains at least oneamino acid substitution, insertion or deletion in the binding unit VH1;

(ii) a second IL-2Rγ binding polypeptide:

(c) a binding unit VL2 consisting of an amino acid sequence of SEQ IDNO:67 or 71, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL2, and

(d) a binding unit VH2 consisting of an amino acid sequence of SEQ IDNO:76 or 78, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH2.

2. The isolated IL-2R bispecific antigen binding protein as defined inpara 1, wherein the said first IL-2Rβ binding polypeptide and saidsecond IL-2Rγ binding polypeptide are linked by a peptide linker.

3. The isolated IL-2R bispecific antigen binding protein as defined inpara 2, wherein the said peptide linker is from 5-23 amino acids inlength.

4. The isolated IL-2R bispecific antigen binding protein as defined inpara 1, wherein said first IL-2Rβ binding polypeptide further comprisesan Fc portion comprising a CH3 domain, in which the CH3 domain comprisesor consists of an amino acid sequence of SEQ ID NO:92, and wherein saidsecond IL-2Rγ binding polypeptide further comprises an Fc portioncomprising a CH3 domain, in which the CH3 domain comprises or consistsof an amino acid sequence of SEQ ID NO:94.

5. The isolated IL-2R bispecific antigen binding protein as defined inpara 4, wherein said first and second polypeptides meet at an engineeredinterface within the CH3 domains, wherein the first polypeptidecomprises at least one engineered protuberance in said interface, saidprotuberance comprising at least one altered contact residue and thesecond polypeptide comprises at least one engineered cavity in its saidinterface, said cavity comprising at least one altered contact residueso as to form a protuberance-into-cavity pairing.

6. The isolated IL-2R bispecific antigen binding protein as defined inpara 4 or para 5, wherein the said binding units are linked to said Fcportion by a linker.

7. The isolated IL-2R bispecific antigen binding protein as defined inpara 6, wherein said linker is from 5-23 amino acids in length.

8. The isolated, IL-2R bispecific antigen binding protein as defined inany one of paras 4 to 7 comprising:

(i) a first IL-2R binding polypeptide:

(a) a binding unit VL1 consisting of an amino acid sequence of SEQ IDNO:1, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL1;

(b) a binding unit VH1 consisting of an amino acid sequence of SEQ IDNO:35, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH1;

(c) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:92, and

(ii) a second IL-2Rγ binding polypeptide:

(d) a binding unit VL2 consisting of an amino acid sequence of SEQ IDNO: 67, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL2;

(e) a binding unit VH2 consisting of an amino acid sequence of SEQ IDNO: 76, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH2, and

(f) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:94.

9. The isolated IL-2R bispecific antigen binding protein as defined inpara 8, wherein said binding protein has a dissociation constant (K_(D))to human IL-2Rβ of 1.46×10⁻⁷M and a dissociation constant (K_(D)) tohuman IL-2Rγ of 2.09×10⁻⁸M.

10. The isolated, IL-2R bispecific antigen binding protein as defined inany one of paras 4 to 7 comprising:

(i) a first IL-2Rβ binding polypeptide:

(a) a binding unit VL1 consisting of an amino acid sequence of SEQ IDNO:5, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL1;

(b) a binding unit VH1 consisting of an amino acid sequence of SEQ IDNO:39, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH1;

(c) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:92, and

(ii) a second IL-2Rγ binding polypeptide:

(d) a binding unit VL2 consisting of an amino acid sequence of SEQ IDNO:71, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL2;

(e) a binding unit VH2 consisting of an amino acid sequence of SEQ IDNO:78, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH2, and

(f) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:94.

11. The isolated IL-2R bispecific antigen binding protein defined inpara 10, wherein said binding protein has a dissociation constant(K_(D)) to human IL-2Rβ of 1.01×10⁻⁷M and a dissociation constant(K_(D)) to human IL-2Rγ of 7.98×10⁻⁸M.

12. The isolated, IL-2R bispecific antigen binding protein as defined inany one of paras 4 to 7 comprising:

(i) a first IL-2R binding polypeptide:

(a) a binding unit VL1 consisting of an amino acid sequence of SEQ IDNO: 9, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL1;

(b) a binding unit VH1 consisting of an amino acid sequence of SEQ IDNO: 43, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH1;

(c) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID N0:92, and

(ii) a second IL-2Rγ binding polypeptide:

(d) a binding unit VL2 consisting of an amino acid sequence of SEQ IDNO:67, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL2;

(e) a binding unit VH2 consisting of an amino acid sequence of SEQ IDNO:76, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH2, and

(f) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:94.

13. The isolated IL-2R bispecific antigen binding protein defined inpara 12, wherein said binding protein has a dissociation constant(K_(D)) to human IL-2Rβ of 1.81×10⁻⁷ M and a dissociation constant(K_(D)) to human IL-2Rγ of 7.87×10⁻⁸ M

14. The isolated, IL-2R bispecific antigen binding protein as defined inany one of paras 4 to 7 comprising:

(i) a first IL-2Rβ binding polypeptide:

(a) a binding unit VL1 consisting of an amino acid sequence of SEQ IDNO:13, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL1;

(b) a binding unit VH1 consisting of an amino acid sequence of SEQ IDNO:47, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH 1;

(c) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:92, and

(ii) a second IL-2Rγ binding polypeptide:

(d) a binding unit VL2 consisting of an amino acid sequence of SEQ IDNO:67, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VL2;

(e) a binding unit VH2 consisting of an amino acid sequence of SEQ IDNO:76, or a variant thereof which contains at least one amino acidsubstitution, insertion or deletion in the binding unit VH2, and

(f) an Fc portion comprising a CH3 domain, in which the CH3 domaincomprises or consists of an amino acid sequence of SEQ ID NO:94.

15. The isolated IL-2R bispecific antigen binding protein as defined inpara 14, wherein said binding protein has a dissociation constant(K_(D)) to human IL-2Rβ of 1.28×10⁻⁷ M and a dissociation constant(K_(D)) to human IL-2Rγ of 3.37×10⁻⁷ M.

16. The isolated IL-2R bispecific antigen binding protein as defined inany one of paras 1 to 15, wherein the IL-2R is human or simian IL-2R.

17. The isolated IL-2R bispecific antigen binding protein as defined inany one of paras 1 to 16, wherein said antigen binding protein is fullyhuman.

18. The isolated IL-2R bispecific antigen binding protein as defined inany one of paras 1 to 17, wherein said binding protein further comprisesan agent selected from the group consisting of an immunoadhesionmolecule, an imaging agent, a therapeutic agent, and a cytotoxic agent.

19. The isolated IL-2R bispecific antigen binding protein of para 18,wherein said agent is an imaging agent selected from the groupconsisting of a radiolabel, an enzyme, a fluorescent label, aluminescent label, a bioluminescent label, a magnetic label, and biotin.

20. The isolated IL-2R bispecific antigen binding protein of para 18,wherein said agent is a therapeutic or cytotoxic agent selected from thegroup consisting of an antimetabolite, an alkylating agent, anantibiotic, an antiviral agent, a growth factor, a cytokine, ananti-angiogenic agent, an anti-mitotic agent, an anthracycline, toxinand an apoptotic agent.

21. The isolated IL-2R bispecific antigen binding protein as defined inany one of paras 1 to 20, wherein said binding protein is an agonist ofIL-2R.

22. A method of treating an infectious disease or cancer in a subject,comprising administering the isolated antigen binding protein as definedin any one of paras 1 to 21 to a subject in need of such treatment.

23. The method as defined in para 22, wherein the cancer is melanoma,renal carcinoma cancer or bladder cancer.

24. Use of the isolated antigen binding protein as defined in any one ofparas 1 to 21, in the manufacture of a medicament for treating aninfectious disease or cancer.

25. The use as defined in para 24, wherein the cancer is melanoma, renalcarcinoma cancer or bladder cancer.

26. A composition comprising the isolated IL-2R bispecific antigenbinding protein as defined in any one of paras 1 to 21 and apharmaceutically acceptable carrier.

27. The composition of para 26, further comprising one or moretherapeutic agents.

28. The composition of para 27, wherein said one or more therapeuticagents are selected from antibiotic agents, antiviral agents, antifungalagents, chemotherapeutic agents, small molecule inhibitors,immunotherapy agents, vaccines, adoptive cell therapy agents, immunecheckpoint inhibitors or antibody therapeutics.

29. An isolated cell line that is capable of producing the isolatedIL-2R bispecific antigen binding protein as defined in any one of paras1 to 21.

30. A kit comprising the isolated IL-2R bispecific antigen bindingprotein as defined in any one of paras 1 to 21, together withinstructions for use.

DESCRIPTION

The present invention encompasses the nucleotide and amino acidsequences of a bispecific antibody with specificity for interleukin-2receptor (IL-2R) chains β and γ, able to stimulate cells expressing themedium affinity IL-2R β-γ and not preferentially cells expressing thehigh affinity IL-2R α-β-γ.

This disclosure describes the design of an IL-2Rα-independent IL-2Ragonist in which receptor activation is achieved throughheterodimerization of the β-γ_(c) components by bispecific antibodies(or bi-functional proteins) possessing anti-IL-2Rβ (CD122) andanti-γ_(c) (CD132) specificities. Use of such molecules can conveydesired immune stimulation by activation of immune cells, particularlythe T cells, without preferential and high activation of cellsexpressing the high affinity α-β-γ_(c) IL-2R. Such molecules would beuseful as vaccine adjuvants.

Isolated nucleotide and amino-acid sequences for two fully humanmonoclonal antibodies binding to IL-2Rβ (CD122) or IL-2Rγ_(c) (CD132)are described.

Nucleotide and amino-acid sequences of the engineered antibody showingmonovalent specificity for IL-2Rβ and IL-2Rγ_(c) are described.

Bispecific antibody construct containing variable domains derived fromthe aforementioned isolated monoclonal antibodies and able to bind bothIL-2Rβ and IL-2Rγ_(c) are described.

Bifunctional protein containing IL-2Rβ and IL-2Rγ binding domainsderived from the sequences of the aforementioned isolated monoclonalantibodies are described.

An antibody or a bifunctional protein binding to the IL-2Rβ/γ_(c) andtriggering phosphorylation of STAT5 and/or Akt is described.

An antibody or a bifunctional protein binding to the IL-2Rβ/γ_(c) andnot binding to the IL-2Rα/β/γ_(c) (CD25) with higher affinity isdescribed.

An antibody or a bifunctional protein agonistically binding to theIL-2Rβ/γ_(c) and triggering intracellular signalling, andantagonistically binding to the IL-2Rα/β/γ_(c) (CD25) without triggeringintracellular signalling is described.

The use of any of these molecules in the treatment of cancers orinfectious diseases, alone or in combination with anti-cancer oranti-infectious drugs is described.

Antibodies

Antibodies according to the present invention preferably bind to CD122(interleukin 2 receptor β (IL-2Rβ)) and/or common γ chain (γc). In someembodiments, the antibody/fragment binds to human CD122 and/or human γc.In some embodiments, the antibody/fragment binds to non-human primateCD122 and/or non-human primate γc.

By “antibody” we include a fragment or derivative thereof, or asynthetic antibody or synthetic antibody fragment. Antibodies accordingto the present invention may be provided in isolated form.

In view of today's techniques in relation to monoclonal antibodytechnology, antibodies can be prepared to most antigens. Theantigen-binding portion may be a part of an antibody (for example a Fabfragment) or a synthetic antibody fragment (for example a single chainFv fragment [ScFv]). Suitable monoclonal antibodies to selected antigensmay be prepared by known techniques, for example those disclosed in“Monoclonal Antibodies: A manual of techniques”, H Zola (CRC Press,1988) and in “Monoclonal Hybridoma Antibodies: Techniques andApplications”, J G R Hurrell (CRC Press, 1982). Chimeric antibodies arediscussed by Neuberger et al (1988, 8th International BiotechnologySymposium Part 2, 792-799).

Monoclonal antibodies (mAbs) are useful in the methods of the inventionand are a homogenous population of antibodies specifically targeting asingle epitope on an antigen.

Antigen binding fragments of antibodies, such as Fab and Fab₂ fragmentsmay also be used/provided as can genetically engineered antibodies andantibody fragments. The variable heavy (V_(H)) and variable light(V_(L)) domains of the antibody are involved in antigen recognition, afact first recognised by early protease digestion experiments. Furtherconfirmation was found by “humanisation” of rodent antibodies. Variabledomains of rodent origin may be fused to constant domains of humanorigin such that the resultant antibody retains the antigenicspecificity of the rodent parent antibody (Morrison et al (1984) Proc.Natl. Acad. Sd. USA 81, 6851-6855).

That antigenic specificity is conferred by variable domains and isindependent of the constant domains is known from experiments involvingthe bacterial expression of antibody fragments, all containing one ormore variable domains. These molecules include Fab-like molecules(Better et al (1988) Science 240, 1041); Fv molecules (Skerra et al(1988) Science 240, 1038); single-chain Fv (ScFv) molecules where theV_(H) and V_(L) partner domains are linked via a flexible oligopeptide(Bird et al (1988) Science 242, 423; Huston et al (1988) Proc. Natl.Acad. Sd. USA 85, 5879) and single domain antibodies (dAbs) comprisingisolated V domains (Ward et al (1989) Nature 341, 544). A general reviewof the techniques involved in the synthesis of antibody fragments whichretain their specific binding sites is to be found in Winter & Milstein(1991) Nature 349, 293-299.

By “ScFv molecules” we mean molecules wherein the V_(H) and V_(L)partner domains are covalently linked, e.g. by a flexible oligopeptide.

Fab, Fv, ScFv and dAb antibody fragments can all be expressed in andsecreted from E. coli, thus allowing the facile production of largeamounts of the said fragments.

Whole antibodies, and F(ab′)₂ fragments are “bivalent”. By “bivalent” wemean that the said antibodies and F(ab′)₂ fragments have two antigencombining sites. In contrast, Fab, Fv, ScFv and dAb fragments aremonovalent, having only one antigen combining site.

The present invention provides an antibody or antigen binding fragmentwhich is capable of binding to CD122 and γc. In some embodiments, theantibody/fragment is a bispecific antibody or a bispecific antigenbinding fragment. In some embodiments, the bispecific antibody orbispecific antigen binding fragment may be isolated.

In some embodiments, the bispecific antibodies and bispecific antigenbinding fragments comprise an antibody/fragment which is capable ofbinding to CD122, e.g. an antibody/fragment as described herein.

In some embodiments, the bispecific antibodies and bispecific antigenbinding fragments comprise an antibody/fragment which is capable ofbinding to γc, e.g. an antibody/fragment as described herein.

In some embodiments, the bispecific antibodies/fragments comprise anantibody/fragment capable of binding to CD122, and an antibody/fragmentcapable of binding to another target protein.

In some embodiments, the bispecific antibodies/fragments comprise anantibody/fragment capable of binding to γc, and an antibody/fragmentcapable of binding to another target protein.

The antigen binding fragment capable of binding to another targetprotein may be capable of binding to another protein other than CD122 orγc.

In one aspect of the present invention a bispecific antibody isprovided, which binds γc but does not bind to CD122.

An antigen-binding fragment of a bispecific antibody/fragment accordingto the present invention may be any fragment of a polypeptide which iscapable of binding to an antigen.

In some embodiments, an antigen binding fragment comprises at least thethree light chain complementarity determining regions (CDRs) (i.e.LC-CDR1, LC-CDR2 and LC-CDR3) and three heavy chain CDRs (i.e. HC-CDR1,HC-CDR2 and HC-CDR3) which together define the antigen binding region ofan antibody or antigen binding fragment. In some embodiments, an antigenbinding fragment may comprise the light chain variable domain and heavychain variable domain of an antibody or antigen binding fragment. Insome embodiments, an antigen binding fragment may comprise the lightchain polypeptide and heavy chain polypeptide of an antibody or antigenbinding fragment.

Bispecific antibodies and fragments according to the invention may beprovided in any suitable format, such as those formats described inKontermann MAbs 2012, 4(2): 182-197, which is hereby incorporated byreference in its entirety. For example, a bispecific antibody orbispecific antigen binding fragment may be a bispecific antibodyconjugate (e.g. an IgG2, F(ab′)₂ or CovX-Body), a bispecific IgG orIgG-like molecule (e.g. an IgG, scFv₄-Ig, IgG-scFv, scFv-IgG, DVD-Ig,IgG-sVD, sVD-IgG, 2 in 1-IgG, mAb², or Tandemab common LC), anasymmetric bispecific IgG or IgG-like molecule (e.g. a kih IgG, kih IgGcommon LC, CrossMab, kih IgG-scFab, mAb-Fv, charge pair or SEED-body), asmall bispecific antibody molecule (e.g. a Diabody (Db), dsDb, DART,scDb, tandAbs, tandem scFv (taFv), tandem dAbNVHH, triple body, triplehead, Fab-scFv, or F(ab′)₂-scFv₂), a bispecific Fc and C_(H)3 fusionprotein (e.g. a taFv-Fc, Di-diabody, scDb-C_(H)3, scFv-Fc-scFv,HCAb-VHH, scFv-kih-Fc, or scFv-kih-C_(H)3), or a bispecific fusionprotein (e.g. a scFv₂-albumin, scDb-albumin, taFv-toxin, DNL-Fab₃,DNL-Fab₄-IgG, DNL-Fab₄-IgG-cytokine₂). See in particular FIG. 2 ofKontermann MAbs 2012, 4(2): 182-19.

In some embodiments an scFv dimer format is preferred in which two scFv,each exhibiting specific binding for a different antigen, are connectedby a linker, e.g. as illustrated in FIG. 25A, right.

A linker may be an amino acid sequence of any desired length, e.g. oneof 2 to 50 amino acids, 5 to 50 amino acids, 5 to 40 amino acids, 5 to30 amino acids, 5 to 20 amino acids, or 5 to 10 amino acids.

The skilled person is able to design and prepare bispecific antibodiesand bispecific antigen binding fragments according to the presentinvention. Methods for producing bispecific antibodies includechemically crosslinking of antibodies or antibody fragments, e.g. withreducible disulphide or non-reducible thioether bonds, for example asdescribed in Segal and Bast, 2001. Production of Bispecific Antibodies.Current Protocols in Immunology. 14:IV:2.13:2.13.1-2.13.16, which ishereby incorporated by reference in its entirety. For example,N-succinimidyl-3-(-2-pyridyldithio)-propionate (SPDP) can be used tochemically crosslink e.g. Fab fragments via hinge region SH— groups, tocreate disulfide-linked bispecific F(ab)₂ heterodimers.

Other methods for producing bispecific antibodies include fusingantibody-producing hybridomas e.g. with polyethylene glycol, to producea quadroma cell capable of secreting bispecific antibody, for example asdescribed in D. M. and Bast, B. J. 2001. Production of BispecificAntibodies. Current Protocols in Immunology. 14:IV:2.13:2.13.1-2.13.16.

Bispecific antibodies and bispecific antigen binding fragments accordingto the present invention can also be produced recombinantly, byexpression from e.g. a nucleic acid construct encoding polypeptides forthe antigen binding molecules, for example as described in AntibodyEngineering: Methods and Protocols, Second Edition (Humana Press, 2012),at Chapter 40: Production of Bispecific Antibodies: Diabodies and TandemscFv (Hornig and Farber-Schwarz), or French, How to make bispecificantibodies, Methods Mol. Med. 2000; 40:333-339, the entire contents ofboth of which are hereby incorporated by reference.

For example, a DNA construct encoding the light and heavy chain variabledomains for the two antigen binding fragments (i.e. the light and heavychain variable domains for the antigen binding fragment capable ofbinding CD122 or γc, and the light and heavy chain variable domains forthe antigen binding fragment capable of binding to another targetprotein), and including sequences encoding a suitable linker ordimerization domain between the antigen binding fragments can beprepared by molecular cloning techniques. Recombinant bispecificantibody can thereafter be produced by expression (e.g. in vitro) of theconstruct in a suitable host cell (e.g. a mammalian host cell), andexpressed recombinant bispecific antibody can then optionally bepurified.

Antibodies may be produced by a process of affinity maturation in whicha modified antibody is generated that has an improvement in the affinityof the antibody for antigen, compared to an unmodified parent antibody.Affinity-matured antibodies may be produced by procedures known in theart, e.g., Marks et al., Rio/Technology 10:779-783 (1992); Barbas et al.Proc Nat. Acad. Sci. USA 91:3809-3813 (1994); Schier et al. Gene169:147-155 (1995); Yelton et al. J. Immunol. 155:1994-2004 (1995);Jackson et al., J. Immunol. 154(7):331 0-15 9 (1995); and Hawkins et al,J. Mol. Biol. 226:889-896 (1992).

Antibodies according to the present invention may exhibit specificbinding to CD122, and/or γc.

An antibody that specifically binds to a target molecule preferablybinds the target with greater affinity, and/or with greater durationthan it binds to other targets. In some embodiments the presentantibodies may bind with greater affinity to CD122 and/or γc than to oneor more members of the type I cytokine receptor family. In someembodiments, the extent of binding of an antibody to an unrelated targetis less than about 10% of the binding of the antibody to the target asmeasured, e.g., by ELISA, SPR, Bio-Layer Interferometry or by aradioimmunoassay (RIA). Alternatively, the binding specificity may bereflected in terms of binding affinity where the anti-CD122 and/or γcantibody of the present invention binds to CD122 and/or γc with a K_(D)that is at least 0.1 order of magnitude (i.e. 0.1×10^(n), where n is aninteger representing the order of magnitude) greater than the K_(D) ofthe antibody towards another target molecule. This may optionally be oneof at least 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.5, or 2.0.

Binding affinity of an antibody for its target is often described interms of its dissociation constant (K_(D)). Binding affinity can bemeasured by methods known in the art, such as by ELISA, Surface PlasmonResonance (SPR; see e.g. Hearty et al., Methods Mol Biol (2012)907:411-442), Bio-Layer Interferometry (see e.g. Lad et al., (2015) JBiomol Screen 20(4): 498-507), or by a radiolabeled antigen bindingassay (RIA) performed with the Fab version of the antibody and antigenmolecule.

In some embodiments, the antibody according to the present invention hasa dissociation constant (K_(D)) for CD122 of one of ≤1×10⁻⁶ M, ≤7.5×10⁻⁷M, ≤5×10⁻⁷ M, ≤4.5×10⁻⁷ M, ≤4×10⁻⁷ M, ≤5×10⁻⁷ M, ≤4.5×10⁻⁷ M, ≤3×10⁻⁷ M,≤3.5×10⁻⁷ M, ≤3×10⁻⁷ M, ≤2.5×10⁻⁷ M, ≤2×10⁻⁷ M, ≤1.9×10⁻⁷ M, ≤1.8×10⁻⁷M, ≤1.7×10⁻⁷ M, ≤1.6×10⁻⁷ M, ≤1.5×10⁻⁷ M, ≤1.4×10⁻⁷ M, ≤1.3×10⁻⁷ M,≤1.2×10⁻⁷ M, ≤1.1×10⁻⁷ M, ≤1×10⁻⁷ M, ≤8×10⁻⁸ M, ≤6×10⁻⁸ M, ≤4×10⁻⁸ M, or≤2×10⁻⁸ M.

In some embodiments, the antibody according to the present invention hasa K_(D) for γc of one of ≤10×10⁻⁷ M, ≤7.5×10⁻⁷ M, ≤5×10⁻⁷ M, ≤2.5×10⁻⁷M, ≤1×10⁻⁷ M, ≤9.5×10⁻⁸ M, ≤9×10⁻⁸ M, ≤8.5×10⁻⁸ M, ≤8×10⁻⁸ M, ≤7.5×10⁻⁸M, ≤7×10⁻⁸ M, ≤6.5×10⁻⁸ M, ≤6×10⁻⁸ M, ≤5.5×10⁻⁸ M, ≤5×10⁻⁸ M, ≤4.5×10⁻⁸M, ≤4×10⁻⁸ M, ≤3.5×10⁻⁸ M, ≤3×10⁻⁸ M, ≤2.5×10⁻⁸ M, ≤2×10⁻⁸ M, ≤1.5×10⁻⁸M, ≤1×10⁻⁸ M, ≤8×10⁻⁹ M, ≤6×10⁻⁹ M, ≤4×10⁻⁹ M or ≤2×10⁻⁹ M.

In some embodiments, the antibody according to the present invention hasa K_(D) for CD122 of one of ≤1×10⁻⁶ M, ≤7.5×10⁻⁷ M, ≤5×10⁻⁷ M, ≤4.5×10⁻⁷M, ≤4×10⁻⁷ M, ≤5×10⁻⁷ M, ≤4.5×10⁻⁷ M, ≤3×10⁻⁷ M, ≤3.5×10⁻⁷ M, ≤3×10⁻⁷ M,≤2.5×10⁻⁷ M, ≤2×10⁻⁷ M, ≤1.9×10⁻⁷ M, ≤1.8×10⁻⁷ M, ≤1.7×10⁻⁷ M, ≤1.6×10⁻⁷M, ≤1.5×10⁻⁷ M, ≤1.4×10⁻⁷ M, ≤1.3×10⁻⁷ M, ≤1.2×10⁻⁷ M, ≤1.1×10⁻⁷ M,≤1×10⁻⁷ M, ≤8×10⁻⁸ M, ≤6×10⁻⁸ M, ≤4×10⁻⁸ M, or ≤2×10⁻⁸ M and a K_(D) forγc of one of ≤10×10⁻⁷ M, ≤7.5×10⁻⁷ M, ≤5×10⁻⁷ M, ≤2.5×10⁻⁷ M, ≤1×10⁻⁷ M,≤9.5×10⁻⁸ M, ≤9×10⁻⁸ M, ≤8.5×10⁻⁸ M, ≤8×10⁻⁸ M, ≤7.5×10⁻⁸ M, ≤7×10⁻⁸ M,≤6.5×10⁻⁸ M, ≤6×10⁻⁸ M, ≤5.5×10⁻⁸ M, ≤5×10⁻⁸ M, ≤4.5×10⁻⁸ M, ≤4×10⁻⁸ M,≤3.5×10⁻⁸ M, ≤3×10⁻⁸ M, ≤2.5×10⁻⁸ M, ≤2×10⁻⁸ M, ≤1.5×10⁻⁸ M, ≤1×10⁻⁸ M,≤8×10⁻⁹ M, ≤6×10⁻⁹ M, ≤4×10⁻⁹ M or 2×10⁻⁹ M.

In some embodiments, the antibody according to the present inventionbinds to CD122 and/or γc expressed at the cell surface of a cellexpressing CD122 and/or γc. Such binding can be analysed by analysis ofbinding of the antibody to PBMCs incubated with the antibody, or cellstransfected with constructs expressing CD122 and/or γc, and subsequentanalysis of antibody binding, e.g. by flow cytometry.

In some embodiments, the antibody according to the present invention isan agonist of one or more signalling pathways which are activated bysignal transduction through receptors comprising CD122 and/or γc, e.g.IL-2 receptor and/or IL-15 receptor. In some embodiments, the antibodyis capable of stimulating signalling through one or more immune receptorcomplexes comprising CD122 and/or γc, e.g. IL-2 receptor and/or IL-15receptor.

In some embodiments, the antibody is an IL-2 receptor agonist.Accordingly in some embodiments, the antibody is capable of activatingIL-2/IL-2 receptor-mediated signalling and associated functions. Forexample, the in some embodiments, the antibody is capable of promotingcell division/proliferation/survival of a cell expressing the IL-2receptor.

In some embodiments, the antibody is an IL-15 receptor agonist.Accordingly in some embodiments, the antibody is capable of activatingIL-15/IL-15 receptor-mediated signalling and associated functions. Forexample, the in some embodiments, the antibody is capable of promotingcell division/proliferation/survival of a cell expressing the IL-15receptor.

In some embodiments bispecific antibodies according to the presentinvention may preferentially bind (e.g. with greater affinity and/orspecificity) receptors comprising or consisting of CD122 and γc comparedto receptors that further comprise CD25. Bispecific antibodies maypreferentially stimulate receptors (or cells expressing receptors)comprising or consisting of CD122 and γc, but not further comprisingCD25.

In some embodiments bispecific antibodies according to the presentinvention that bind CD122 and γc preferably do not exhibit significantinhibition of ligand binding to receptors having the common gamma chainand not containing CD122, e.g. receptors other than IL-2R and IL-15R.For example, bispecific antibodies according to the present inventionmay be specific for receptors comprising both CD122 and γc overreceptors that comprise γc but do not comprise CD122.

In some embodiments, the antibody according to the present invention iscapable of stimulating CD122:γc mediated signalling through one of moreof the following intracellular signalling pathways: STAT5, Akt, ERK.Signalling through STAT5, Akt, ERK intracellular signalling pathways canbe analysed by methods well known to the skilled person, such as e.g. bydetection of phosphorylated STAT5, phosphorylated Akt and optionallyphosphorylated ERK, respectively following stimulation of cellsexpressing CD122 and/or γc with the antibody.

In some embodiments, the antibody according to the present invention isa less potent stimulator of intracellular signalling in Treg cells thanIL-2. For example, treatment with the antibody may result in lessphosphorylation of STAT5 as compared to treatment with IL-2.

In some embodiments, the antibody is capable of stimulatingproliferation of immune cells in vitro and or in vivo. Stimulation ofproliferation results in an increase in the number of the cell typewhose proliferation is stimulated, effective to achieve expansion of thecell population. For example, the antibody is useful in stimulatingproliferation and/or expansion of leukocytes in vitro or in vivo,preferably exhibiting reduced toxicity when compared to the effects of acorresponding amount of IL-2.

In some embodiments, the antibody is capable of stimulatingproliferation of IL-2 dependent cells. In some embodiments, the antibodyis capable of stimulating proliferation of CD3+ T cells (e.g. CD4+ Tcells, CD8+ T cells) and/or NK cells.

Whether an antibody is capable of stimulating proliferation of cells canbe analysed in vitro by methods well known in the art, such as byanalysis of the number of a given cell type before and afterstimulation, and/or by another assay, such as thymidine incorporation,CFSE dilution (e.g. as described in Anthony et al., 2012 Cells1:127-140), AlamarBlue signal etc.

In some embodiments, the antibody according to the present invention iscapable of binding to non-human primate (e.g. cynomolgous macaque) CD122and/or γc. The antibody may be cross-reactive for human and non-humanprimate CD122 and/or γc. Accordingly, in some embodiments, the antibodyis capable of stimulating IL-2/IL-2 receptor- and/or IL-15/IL-15receptor-mediated mediated signalling in cells expressing non-humanprimate (e.g. cynomolgous macaque) CD122 and/or γc.

In some embodiments, the antibody of the present invention is capable ofstimulating proliferation of CD3+ T cells. In some embodiments, theantibody of the present invention is capable of stimulatingproliferation of CD4+ T cells. In some embodiments, the antibody of thepresent invention is capable of stimulating proliferation of CD8+ Tcells.

In some embodiments, the antibody of the present invention is capable ofincreasing the ratio of CD8+ T cells to CD4+ T cells. That is, in someembodiments, following stimulation (e.g. in vitro or in vivo) of apopulation of cells comprising CD8+ T cells and CD4+ T cells, the ratioof CD8+ T cells to CD4+ T cells may be higher following stimulation ascompared to before stimulation.

In some embodiments, the antibody of the present invention is not apotent stimulator of proliferation of CD4+FoxP3+ cells (i.e. Tregs). Insome embodiments, the antibody does not stimulate proliferation ofTregs.

In some embodiments, the antibody of the invention stimulatesproliferation of Tregs to a lesser extent than IL-2. That is, in someembodiments, the antibody of the invention is a less potent agonist ofproliferation of Tregs than IL-2. In some embodiments, the antibody ofthe invention stimulates proliferation of Tregs to an extent which is ≤1times, ≤0.8 times, ≤0.6 times, ≤0.4 times, ≤0.2 times, ≤0.1 times thelevel of proliferation of Tregs stimulated by treatment with IL-2 at acomparable concentration, in a given assay.

In some embodiments, the antibody of the present inventionpreferentially stimulates proliferation of the effector memory subset ofCD8+ T cells over the central memory CD8+ T cell and naïve CD8+ T cellpopulations.

In some embodiments, the antibody of the present invention stimulatesproliferation of effector memory CD8+ T cells to a greater extent thanIL-2 at a comparable concentration, in a given assay.

In some embodiments, the antibody of the present invention is capable ofstimulating proliferation of antigen-specific T cells, e.g.antigen-specific CD8+ T cells and/or antigen-specific CD4+ T cells.Stimulation may occur in vitro or in vivo. In some embodiments, theantibody of the present invention is capable of stimulatingproliferation of antigen-specific CD8+ cytotoxic T lymphocytes (CTLs).Ability of cells to stimulate proliferation of antigen-specific T cellscan be evaluated e.g. by analysis of proliferation of T cells incubatedwith cells presenting an antigen of interest in the presence of theantibody, e.g. as described in Examples 8 and 11 herein.

In some embodiments, the antibody of the present invention is capable ofstimulating proliferation of antigen-specific T cells to a greaterextent than IL-2 at a comparable concentration, in a given assay.

In some embodiments, the antibody of the present invention is capable ofstimulating proliferation of antigen-specific CD8+ T cells to a greaterextent than IL-2 at a comparable concentration, in a given assay.

In some embodiments, the antibody of the present invention is capable ofincreasing the ratio of antigen-specific CD8+ T cells to CD4+ T cells.This may occur in vitro or in vivo.

That is, in some embodiments, following stimulation (e.g. in vitro) of apopulation of cells comprising antigen-specific CD8+ T cells and CD4+ Tcells, the ratio of CD8+ T cells to CD4+ T cells is higher followingstimulation as compared to before stimulation. In some embodiments, theantibody of the invention is capable of increasing the ratio ofantigen-specific CD8+ T cells to CD4+ T cells to a greater extent thanIL-2 at a comparable concentration, in a given assay.

In some embodiments, the antibody of the present invention is capable ofstimulating proliferation of CD8+PD1+ T cells (e.g. antigen-specificCD8+PD1+ T cells). In some embodiments, the antibody of the presentinvention is capable of stimulating proliferation of CD8+PD1+ T cells toa greater extent than IL-2 at a comparable concentration, in a givenassay.

In some embodiments, the antibody of the present invention is capable ofreducing the proportion of Tregs as a proportion of CD4+ T cells. Thatis, in some embodiments, following treatment of a population of CD4+ Tcells with the antibody, the percentage of the CD4+ T cells which areTregs is reduced. In some embodiments, the antibody of the presentinvention is capable of reducing the proportion of Tregs as a proportionof CD4+ T cells to a greater extent than IL-2 at a comparableconcentration, in a given assay.

In some embodiments, the antibody of the present invention is capable ofstimulating CTL cytotoxicity. Ability of an antibody to stimulate CTLcytotoxicity can be measured by methods known to the skilled person.Cytotoxicity of a T cell to a given target cell can be investigated, forexample, using any of the methods reviewed in Zaritskaya et al. ExpertRev Vaccines (2011), 9(6):601-616, hereby incorporated by reference inits entirety.

In some embodiments, the antibody is capable of stimulating theproliferation of immune cells in vivo. In some embodiments, the antibodyis capable of stimulating the proliferation of CD3+ cells in vivo. Insome embodiments, the antibody is capable of stimulating theproliferation of CD8+ T cells in vivo. In some embodiments, the antibodyis capable of stimulating the proliferation of CD4+ T cells in vivo. Insome embodiments, the antibody is capable of stimulating theproliferation of NK cells in vivo.

In aspects and embodiments of the present invention stimulation orexpansion of cells having desired characteristics may occur in vitro orin vivo. In vitro stimulation or expansion may provide a population ofcells enriched for desired characteristics that may be collected andused for a desired purpose, which may include administration to asubject. In vivo stimulation or expansion may enrich for a population ofcells that are beneficial to the subject, e.g. in treating or preventinga disease. In vivo stimulation or expansion may have an adjuvant effector action.

In some aspects, the antibody of the present invention comprises theantibody/fragment of a CD122-binding antibody clone. In some aspects,the antibody comprises the antibody/fragment of clone P2C4 or a variantof P2C4. In some aspects, the antibody comprises the antibody/fragmentof clone P2C4_A4 or a variant of P2C4_A4. In some aspects, the antibodycomprises the antibody/fragment of clone P2C4_B1 or a variant ofP2C4_B1. In some aspects, the antibody comprises the antibody/fragmentof clone P2C4_B5 or a variant of P2C4_B5. In some aspects, the antibodycomprises the antibody/fragment of clone P2C4_C1 or a variant ofP2C4_C1. In some aspects, the antibody comprises the antibody/fragmentof clone P2C4_C4 or a variant of P2C4_C4. In some aspects, the antibodycomprises the antibody/fragment of clone P2C4_C7 or a variant ofP2C4_C7. In some aspects, the antibody comprises the antibody/fragmentof clone P2C4_D10 or a variant of P2C4_D10. In some aspects, theantibody comprises the antibody/fragment of clone P2C4_E6 or a variantof P2C4_E6. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_E7 or a variant of P2C4_E7. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_F8or a variant of P2C4_F8. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_C1D10 or a variant of P2C4_C1D10. Insome aspects, the antibody comprises the antibody/fragment of cloneP2C4_FW2 or a variant of P2C4_FW2. In some aspects, the antibodycomprises the antibody/fragment of clone P2H7 or a variant of P2H7. Insome aspects, the antibody comprises the antibody/fragment of cloneP2D12 or a variant of P2D12. In some aspects, the antibody comprises theantibody/fragment of clone P1G11 or a variant of P1G11. In some aspects,the antibody comprises the antibody/fragment of clone P2C4_A9 or avariant of P2C4_A9. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_B6 or a variant of P2C4_B6. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_E9or a variant of P2C4_E9. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_B8 or a variant of P2C4_B8. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_B12or a variant of P2C4_B12. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_C12 or a variant of P2C4_C12. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_E2or a variant of P2C4_E2. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_E3 or a variant of P2C4_E3. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_E8or a variant of P2C4_E8. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_F11 or a variant of P2C4_F11. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_G2or a variant of P2C4_G2. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_G11 or a variant of P2C4_G11. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_H1or a variant of P2C4_H1. In some aspects, the antibody comprises theantibody/fragment of clone P2C4_H2 or a variant of P2C4_H2. In someaspects, the antibody comprises the antibody/fragment of clone P2C4_H3or a variant of P2C4_H3.

The amino acid sequences of the VL domains of the CD122-binding antibodyclones of the preceding paragraph are shown in FIG. 1, as are the CDRsdefined according to the Kabat system. The amino acid sequences of theVH domains of the CD122-binding antibody clones of the precedingparagraph are shown in FIG. 2, as are the CDRs defined according to theKabat system. The full amino acid sequences of the antibody constructs(including linkers) are shown in FIG. 15, and the encoding nucleotidesequences are shown in FIG. 17.

Antibodies according to the present invention may comprise the CDRs ofP2C4, P2C4_A4, P2C4_B1, P2C4_B5, P2C4_C1, P2C4_C4, P2C4_C7, 2C4_D10,P2C4_E6, P2C4_E7, P2C4_F8, P2C4_C1D10, P2C4_FW2, P2H7, P2D12, P1G11,P2C4_A9, P2C4_B6, P2C4_E9, P2C4_B8, P2C4_B12, P2C4_C12, P2C4_E2,P2C4_E3, P2C4_E8, P2C4_F11, P2C4_G2, P2C4_G11, P2C4_H1, P2C4_H2, orP2C4_H3. In an antibody according to the present invention one or two orthree or four of the six CDR sequences may vary. A variant may have oneor two amino acid substitutions in one or two of the six CDR sequences.

Antibodies according to the present invention may comprise VL and/or VHchains comprising an amino acid sequence that has a high percentagesequence identity to one or more of the VL and/or VH amino acidsequences shown in FIGS. 1 and 2, respectively. For example, antibodiesaccording to the present invention include antibodies that bind CD122and have a VL chain that comprises an amino acid sequence having atleast 70%, more preferably one of at least 75%, 80%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%, sequenceidentity to the VL chain amino acid sequence of one of SEQ ID NOs:1, 17,19, 21, 23, 24, 27, 28, 29, 30, 31, 33, 34, 148, 149, 5, 9, or 13 shownin FIG. 1. Antibodies according to the present invention includeantibodies that bind CD122 and have VH chain that comprises an aminoacid sequence having at least 70%, more preferably one of at least 75%,80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, 99%, or 100%, sequence identity to the VH chain amino acid sequenceof one of SEQ ID NOs:35, 51, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64,65, 66, 150, 151, 39, 43, or 47 shown in FIG. 2.

Antibodies according to the present invention include an antibody orCD122-binding fragment thereof having the amino acid sequence encoded bythe nucleotide sequence of any one of SEQ ID NOs:130, 131, 132, 133,134, 135, 136, 137, 138, 139, 140, or 141 shown in FIG. 17. Antibodiesof the present invention include an antibody comprising the VL and/or VHdomain sequence of an amino acid sequence encoded by the nucleotidesequence of any one of SEQ ID NOs:130, 131, 132, 133, 134, 135, 136,137, 138, 139, 140, or 141 shown in FIG. 17.

In some aspects, the antibody of the present invention comprises theantibody/fragment of a γc-binding antibody clone. In some aspects, theantibody comprises the antibody/fragment of clone P1A3 or a variant ofP1A3. In some aspects, the antibody comprises the antibody/fragment ofclone P1A3_B3 or a variant of P1A3_B3. In some aspects, the antibodycomprises the antibody/fragment of clone P1A3_E8 or a variant ofP1A3_E8. In some aspects, the antibody comprises the antibody/fragmentof clone P1A3_E9 or a variant of P1A3_E9. In some aspects, the antibodycomprises the antibody/fragment of clone P1A3_B4 or a variant ofP1A3_B4. In some aspects, the antibody comprises the antibody/fragmentof clone P1A3_FW2 or a variant of P1A3_FW2. In some aspects, theantibody comprises the antibody/fragment of clone P2B9 or a variant ofP2B9.

The amino acid sequences of the VL domains of the γc-binding antibodyclones of the preceding paragraph are shown in FIG. 3, as are the CDRsdefined according to the Kabat system. The amino acid sequences of theVH domains of the γc-binding antibody clones of the preceding paragraphare shown in FIG. 4, as are the CDRs defined according to the Kabatsystem. The full amino acid sequences of the antibody constructs(including linkers) are shown in FIG. 16, and the encoding nucleotidesequences are shown in FIG. 18.

Antibodies according to the present invention may comprise the CDRs ofP1A3, P1A3_B3 P1A3_E8, P1A3_E9, P1A3_B4, P1A3_FW2, or P2B9. In anantibody according to the present invention one or two or three or fourof the six CDR sequences may vary. A variant may have one or two aminoacid substitutions in one or two of the six CDR sequences.

Antibodies according to the present invention may comprise VL and/or VHchains comprising an amino acid sequence that has a high percentagesequence identity to one or more of the VL and/or VH amino acidsequences shown in FIGS. 3 and 4, respectively. For example, antibodiesaccording to the present invention include antibodies that bind γc andhave VL chain that comprises an amino acid sequence having at least 70%,more preferably one of at least 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%, sequence identityto the VL chain amino acid sequence of one of SEQ ID NOs:67, 152, 71, or75 shown in FIG. 3. Antibodies according to the present inventioninclude antibodies that bind γc and have VH chain that comprises anamino acid sequence having at least 70%, more preferably one of at least75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, 99%, or 100%, sequence identity to the VH chain amino acidsequence of one of SEQ ID NOs:76, 153, 78, 82 or 84 shown in FIG. 4.

Antibodies according to the present invention include an antibody orγc-binding fragment thereof having the amino acid sequence encoded bythe nucleotide sequence of any one of SEQ ID NOs:142, 143, 144, 145,146, or 147 shown in FIG. 18. Antibodies of the present inventioninclude an antibody comprising the VL and/or VH domain sequence of anamino acid sequence encoded by the nucleotide sequence of any one of SEQID NOs:142, 143, 144, 145, 146, or 147 shown in FIG. 18.

In some aspects, the antibody of the present invention comprises theantibody/fragment of a CD122-binding antibody clone, e.g. aCD122-binding antibody clone as described, and also comprises aγc-binding clone, e.g. a γc-binding clone as described herein.

The light and heavy chain CDRs disclosed herein may also be particularlyuseful in conjunction with a number of different framework regions.Accordingly, light and/or heavy chains having LC-CDR1-3 or HC-CDR1-3 maypossess an alternative framework region. Suitable framework regions arewell known in the art and are described for example in M. Lefranc & G.Le:franc (2001) “The Immunoglobulin FactsBook”, Academic Press,incorporated herein by reference.

Antibodies according to the present invention may be detectably labelledor, at least, capable of detection. For example, the antibody may belabelled with a radioactive atom or a coloured molecule or a fluorescentmolecule or a molecule which can be readily detected in any other way.Suitable detectable molecules include fluorescent proteins, luciferase,enzyme substrates, and radiolabels. The binding moiety may be directlylabelled with a detectable label or it may be indirectly labelled. Forexample, the binding moiety may be an unlabelled antibody which can bedetected by another antibody which is itself labelled. Alternatively,the second antibody may have bound to it biotin and binding of labelledstreptavidin to the biotin is used to indirectly label the firstantibody.

Chimeric Antigen Receptors

The present invention provides a chimeric antigen receptor (CAR) capableof binding to CD122 and/or γc. The CAR comprises one or more antigenbinding fragments or polypeptides according to the present invention.

Chimeric Antigen Receptors (CARs) are recombinant receptors that provideboth antigen-binding and T cell activating functions. CAR structure andengineering is reviewed, for example, in Dotti et al., Immunol Rev(2014) 257(1), hereby incorporated by reference in its entirety.

Antigen-binding fragments according to the present invention areprovided herein as the antigen-binding domain of a chimeric antigenreceptor (CAR). In some embodiments, the CAR comprises a VL domain and aVH domain according to any embodiment of an antibody, antigen bindingfragment or polypeptide described herein. Accordingly, the antigen boundby the CAR according to the present invention is CD122 and/or γc.

CARs may be combined with costimulatory ligands, chimeric costimulatoryreceptors or cytokines to further enhance T cell potency, specificityand safety (Sadelain et al., The basic principles of chimeric antigenreceptor (CAR) design. Cancer Discov. 2013 April; 3(4): 388-398.doi:10.1158/2159-8290.CD-12-0548, specifically incorporated herein byreference).

The present invention also provides a cell comprising a CAR according tothe invention. The CAR according to the present invention may be used togenerate T cells targeted to cells expressing CD122 and/or γc.

Engineering of CARs into T cells may be performed during culture, invitro, for transduction and expansion, such as happens during expansionof T cells for adoptive T cell therapy. The transduction may utilize avariety of methods, but stable gene transfer is required to enablesustained CAR expression in clonally expanding and persisting T cells.

A CAR typically combines an antigen binding domain with an intracellulardomain of the CD3-zeta chain or FcγRI protein in a single chimericprotein. The structural features of a CAR are described by Sjouke etal., (The pharmacology of second-generation chimeric antigen receptors.Nature Reviews Drug Discovery, 14, 499 509 (2015) doi:10.1038/nrd4597).A CAR typically has an extracellular antigen-binding domain linked to atransmembrane domain and endodomain. An optional hinge or spacer domainmay provide separation between the binding moiety and transmembranedomain and may act as a flexible linker.

In accordance with the present invention, the antigen recognition domainof the CAR is, or is derived from, an antibody, antigen binding fragmentor polypeptide which is capable of binding to CD122 and/or γc, asdescribed herein.

Hinge or spacer regions of the CAR may be flexible domains allowing thebinding moiety to orient in different directions. Hinge or spacerregions may be derived from IgG1 or the C_(H)2C_(H)3 region ofimmunoglobulin.

Transmembrane domains may be hydrophobic alpha helix that spans the cellmembrane. The transmembrane domain associated with the endodomain iscommonly used.

The endodomain is responsible for receptor clustering/dimerization afterantigen binding and for initiation of signal transduction to the cell.One commonly used transmembrane domain is the CD3-zeta transmembrane andendodomain. Intracellular domains from one or more co-stimulatoryprotein receptors, such as CD28 4-1BB, OX40, ICOS, may optionally beincorporated into the cytoplasmic tail of the CAR to provide additionalco-stimulatory signaling, which may be beneficial in terms of anti-tumoractivity.

In one embodiment, a CAR comprises an extracellular domain having anantigen recognition domain, a transmembrane domain, and a cytoplasmicdomain. A transmembrane domain that is naturally associated with one ofthe domains in the CAR may be used or the transmembrane domain can beselected or modified by amino acid substitution to avoid binding of suchdomains to the transmembrane domains of the same or different surfacemembrane proteins to minimize interactions with other members of thereceptor complex.

The cytoplasmic domain may be designed to comprise the CD28 and/or 4-1BBsignaling domain by itself or be combined with any other desiredcytoplasmic domain(s). The cytoplasmic domain may be designed to furthercomprise the signaling domain of CD3-zeta. For example, the cytoplasmicdomain of the CAR can include but is not limited to CD3-zeta, 4-1BB andCD28 signaling modules and combinations thereof.

The present invention also provides CAR T cells comprising as a CAR anantigen binding fragment capable of binding to CD122 and/or γc,according to the present invention.

CAR T cells of the invention can be generated by introducing alentiviral vector in vitro comprising a desired CAR, for example a CARcomprising anti-IL2Rβ/γc, CD8a hinge and transmembrane domain, and human4-1BB and CD3zeta signaling domains, into the cells. The CAR T cells ofthe invention are able to replicate in vivo resulting in long-termpersistence that can lead to sustained tumor control.

In one embodiment the invention relates to administering a geneticallymodified T cell expressing a CAR capable of binding to CD122 and/or γcfor the treatment of a patient having cancer or at risk of having canceror an infectious disease using lymphocyte infusion. Preferably,autologous lymphocyte infusion is used in the treatment. AutologousPBMCs are collected from a patient in need of treatment and T cells areactivated and expanded using the methods described herein and known inthe art and then infused back into the patient.

Methods of Detection

Antibodies, or antigen binding fragments, described herein may be usedin methods that involve the binding of the antibody or antigen bindingfragment to CD122 and/or γc. Such methods may involve detection of thebound complex of antibody, or antigen binding fragment, and CD122 and/orγc. As such, in one embodiment a method is provided, the methodcomprising contacting a sample containing, or suspected to contain,CD122 and/or γc with an antibody or antigen binding fragment asdescribed herein and detecting the formation of a complex of antibody,or antigen binding fragment, and CD122 and/or γc.

Suitable method formats are well known in the art, includingimmunoassays such as sandwich assays, e.g. ELISA. The method may involvelabelling the antibody, or antigen binding fragment, or CD122 and/or γc,or both, with a detectable label, e.g. fluorescent, luminescent orradio-label. CD122 and/or γc expression may be measured byimmunohistochemistry (IHC), for example of a tissue sample obtained bybiopsy.

Methods of this kind may provide the basis of a method of diagnosis of adisease or condition requiring detection and or quantitation of CD122and/or γc. Such methods may be performed in vitro on a patient sample,or following processing of a patient sample. Once the sample iscollected, the patient is not required to be present for the in vitromethod of diagnosis to be performed and therefore the method may be onewhich is not practised on the human or animal body.

Such methods may involve determining the amount of CD122 and/or γcpresent in a patient sample. The method may further comprise comparingthe determined amount against a standard or reference value as part ofthe process of reaching a diagnosis. Other diagnostic tests may be usedin conjunction with those described here to enhance the accuracy of thediagnosis or prognosis or to confirm a result obtained by using thetests described here.

The level of CD122 and/or γc present in a patient sample may beindicative that a patient may respond to treatment with an anti-CD122and/or anti-γc antibody. The presence of a high level of CD122 and/or γcin a sample may be used to select a patient for treatment with ananti-CD122 and/or anti-γc antibody. The antibodies of the presentinvention may therefore be used to select a patient for treatment withanti-CD122 and/or anti-γc antibody therapy.

Detection in a sample of anti-CD122 and/or anti-γc antibody may be usedfor the purpose of diagnosis of an infectious disease, autoimmunedisorder or a cancerous condition in the patient, diagnosis of apredisposition to an infectious disease, autoimmune disorder or acancerous condition or for providing a prognosis (prognosticating) of aninfectious disease, autoimmune disorder or a cancerous condition. Thediagnosis or prognosis may relate to an existing (previously diagnosed)infectious disease, autoimmune disorder or cancerous condition.

A sample may be taken from any tissue or bodily fluid. The sample maycomprise or may be derived from: a quantity of blood; a quantity ofserum derived from the individual's blood which may comprise the fluidportion of the blood obtained after removal of the fibrin clot and bloodcells; a tissue sample or biopsy; or cells isolated from saidindividual.

Methods according to the present invention may preferably performed invitro. The term “in vitro” is intended to encompass experiments withcells in culture whereas the term “in vivo” is intended to encompassexperiments with and/or treatment of intact multi-cellular organisms.

Therapeutic Applications

Antibodies, antigen binding fragments and polypeptides according to thepresent invention and compositions comprising such agents may beprovided for use in methods of medical treatment. Treatment may beprovided to subjects having a disease or condition in need of treatment.

Methods of medical treatment may involve treatment of cancer by a methodof ameliorating, treating, or preventing a malignancy in a human subjectwherein the steps of the method assist or boost the immune system ineradicating cancerous cells. Such methods may include the administrationof cells, antibodies, proteins, or nucleic acids according to thepresent invention that invoke an active (or achieve a passive) immuneresponse to destroy cancerous cells. Methods of treatment may optionallyinclude the co-administration of biological adjuvants (e.g.,interleukins, cytokines, Bacillus Comette-Guerin, monophosphoryl lipidA, etc.) in combination with conventional therapies for treating cancersuch as chemotherapy, radiation, or surgery. Methods of treatment mayinvolve administering a composition according to the present inventionas a vaccine that works by activating the immune system to prevent ordestroy cancer cell growth. Methods of medical treatment may alsoinvolve in vivo, ex vivo, and adoptive immunotherapies, including thoseusing autologous and/or heterologous cells or immortalized cell lines.

The disease or condition may be one of an infectious disease, anautoimmune disorder (e.g. e.g. Crohn's disease, Multiple Sclerosis), acancer, an inflammatory disease (e.g. arthritis), a disease/disorderassociated with deficient IL-2-mediated signalling and/or IL-15-mediatedsignalling, deficient T cell proliferation or T cell dysfunction.

In some embodiments, the treatment is of a disease or disorder for whichincreased IL-2-mediated signalling and/or IL-15-mediated signalling istherapeutic.

In some embodiments, the treatment is of a disease or disorderassociated with a deficient T cell response, e.g. a deficient CD8+ Tcell response.

The treatment may be aimed at preventing or treating a disease/disorderby one of more of: increasing the number of CD3+ T cells, increasing thenumber of CD4+ T cells, increasing the number of CD8+ T cells,increasing the number of CD8+ effector T cells (e.g. CTLs), increasingthe number NK cells, increasing the ratio of CD8+ T cells to CD4+ Tcells, or decreasing the proportion of Tregs.

The T-cell dysfunctional disorder may be manifest as an infection, orinability to mount an effective immune response against an infection.The infection may be chronic, persistent, latent or slow, and may be theresult of bacterial, viral, fungal or parasitic infection. As such,treatment may be provided to patients having a bacterial, viral orfungal infection. Examples of bacterial infections include infectionwith Helicobacter pylori. Examples of viral infections include infectionwith EBV, HIV, hepatitis B or hepatitis C.

The T-cell dysfunctional disorder may be associated with a cancer, suchas tumor immune escape. Many human tumors express tumor-associatedantigens recognised by T cells and capable of inducing an immuneresponse.

Cancers may also be treated where there is no indication of a T-celldysfunctional disorder but the use of an antibody, antigen bindingfragment or polypeptide according to the present invention promotes aneffective immune response.

The treatment may be aimed at prevention of a disease/disorderassociated with deficient/reduced IL-2-mediated signalling and/orIL-15-mediated signalling. As such, the antibodies, antigen bindingfragments and polypeptides may be used to formulate pharmaceuticalcompositions or medicaments and subjects may be prophylactically treatedagainst development of a disease state. This may take place before theonset of symptoms of the disease state, and/or may be given to subjectsconsidered to be at greater risk of the disease or disorder.

Treatment may comprise co-therapy with a vaccine, e.g. T-cell vaccine,which may involve simultaneous, separate or sequential therapy, orcombined administration of vaccine and antibody, antigen bindingfragment or polypeptide in a single composition. In this context, theantibody, antigen binding fragment or polypeptide may be provided as anadjuvant to the vaccine.

Administration of an antibody, antigen binding fragment or polypeptideis preferably in a “therapeutically effective amount”, this beingsufficient to show benefit to the individual. The actual amountadministered, and rate and time-course of administration, will depend onthe nature and severity of the disease being treated. Prescription oftreatment, e.g. decisions on dosage etc., is within the responsibilityof general practitioners and other medical doctors, and typically takesaccount of the disorder to be treated, the condition of the individualpatient, the site of delivery, the method of administration and otherfactors known to practitioners. Examples of the techniques and protocolsmentioned above can be found in Remington's Pharmaceutical Sciences,20th Edition, 2000, pub. Lippincott, Williams & Wilkins.

The CARs and cells comprising the CARs (i.e. CAR-T cells) of the presentinvention find use to treat autoimmune disorders, e.g. Crohn's disease,Multiple Sclerosis. In such treatments, the CAR-T cells are effective tokill autoimmune aggressor cells (e.g. autoreactive T cells) expressingCD122 and/or γc.

Formulating Pharmaceutically Useful Compositions and Medicaments

Antibodies, antigen binding fragments, and polypeptides, CARs and cellsaccording to the present invention may be formulated as pharmaceuticalcompositions or medicaments for clinical use and may comprise apharmaceutically acceptable carrier, diluent, excipient or adjuvant.

In accordance with the present invention methods are also provided forthe production of pharmaceutically useful compositions, such methods ofproduction may comprise one or more steps selected from: isolating anantibody, antigen binding fragment, polypeptide, CAR or cell asdescribed herein; and/or mixing an isolated antibody, antigen bindingfragment or polypeptide as described herein with a pharmaceuticallyacceptable carrier, adjuvant, excipient or diluent.

For example, a further aspect of the present invention relates to amethod of formulating or producing a medicament or pharmaceuticalcomposition for use in a method of medical treatment, method comprisingformulating a pharmaceutical composition or medicament by mixing anantibody, antigen binding fragment, polypeptide, CAR or cell asdescribed herein with a pharmaceutically acceptable carrier, adjuvant,excipient or diluent.

Infection

An infection may be any infection or infectious disease, e.g. bacterial,viral, fungal, or parasitic infection. In some embodiments it may beparticularly desirable to treat chronic/persistent infections, e.g.where such infections are associated with T cell dysfunction or T cellexhaustion.

It is well established that T cell exhaustion is a state of T celldysfunction that arises during many chronic infections (including viral,bacterial and parasitic), as well as in cancer (Wherry Nature ImmunologyVol. 12, No. 6, p 492-499, June 2011).

Examples of bacterial infections that may be treated include infectionby Bacillus spp., Bordetella pertussis, Clostridium spp.,Corynebacterium spp., Vibrio chloerae, Staphylococcus spp.,Streptococcus spp. Escherichia, Klebsiella, Proteus, Yersinia, Erwina,Salmonella, Listeria sp, Helicobacter pylori, mycobacteria (e.g.Mycobacterium tuberculosis) and Pseudomonas aeruginosa. For example, thebacterial infection may be sepsis or tuberculosis.

Examples of viral infections that may be treated include infection byEpstein-Barr virus, influenza virus, measles virus, hepatitis B virus(HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV),lymphocytic choriomeningitis virus (LCMV), Herpes simplex virus andhuman papilloma virus.

Examples of fungal infections that may be treated include infection byAlternaria sp, Aspergillus sp, Candida sp and Histoplasma sp. The fungalinfection may be fungal sepsis or histoplasmosis. Examples of parasiticinfections that may be treated include infection by Plasmodium species(e.g. Plasmodium falciparum, Plasmodium yoeli, Plasmodium ovale,Plasmodium vivax, or Plasmodium chabaudi chabaudi). The parasiticinfection may be a disease such as malaria, leishmaniasis andtoxoplasmosis.

Cancer

A cancer may be any unwanted cell proliferation (or any diseasemanifesting itself by unwanted cell proliferation), neoplasm or tumor orincreased risk of or predisposition to the unwanted cell proliferation,neoplasm or tumor. The cancer may be benign or malignant and may beprimary or secondary (metastatic). A neoplasm or tumor may be anyabnormal growth or proliferation of cells and may be located in anytissue. Examples of tissues include the adrenal gland, adrenal medulla,anus, appendix, bladder, blood, bone, bone marrow, brain, breast, cecum,central nervous system (including or excluding the brain) cerebellum,cervix, colon, duodenum, endometrium, epithelial cells (e.g. renalepithelia), gallbladder, oesophagus, glial cells, heart, ileum, jejunum,kidney, lacrimal glad, larynx, liver, lung, lymph, lymph node,lymphoblast, maxilla, mediastinum, mesentery, myometrium, nasopharynx,omentum, oral cavity, ovary, pancreas, parotid gland, peripheral nervoussystem, peritoneum, pleura, prostate, salivary gland, sigmoid colon,skin, small intestine, soft tissues, spleen, stomach, testis, thymus,thyroid gland, tongue, tonsil, trachea, uterus, vulva, white bloodcells.

Tumors to be treated may be nervous or non-nervous system tumors.Nervous system tumors may originate either in the central or peripheralnervous system, e.g. glioma, medulloblastoma, meningioma, neurofibroma,ependymoma, Schwannoma, neurofibrosarcoma, astrocytoma andoligodendroglioma. Non-nervous system cancers/tumors may originate inany other non-nervous tissue, examples include melanoma, mesothelioma,lymphoma, myeloma, leukemia, Non-Hodgkin's lymphoma (NHL), Hodgkin'slymphoma, chronic myelogenous leukemia (CML), acute myeloid leukemia(AML), myelodysplastic syndrome (MDS), cutaneous T-cell lymphoma (CTCL),chronic lymphocytic leukemia (CLL), hepatoma, epidermoid carcinoma,prostate carcinoma, breast cancer, lung cancer, colon cancer, ovariancancer, pancreatic cancer, thymic carcinoma, NSCLC, haematologic cancerand sarcoma.

In particular, treatment of melanoma, kidney cancer (e.g. renalcarcinoma) or bladder cancer is contemplated.

In some embodiments the cancer is an EBV or HPV positive cancer.

Adoptive Cell Transfer Therapy

Adoptive cell transfer therapy generally refers to a process in whichwhite blood cells are removed from a subject, typically by drawing ablood sample from which white blood cells are separated, expanded invitro or ex vivo and returned either to the same subject or to adifferent subject. The treatment is typically aimed at increasing theamount/concentration of an active form of the required cell populationin the subject.

The antibodies/fragments of the present invention provide a means ofexpanding the number and/or enhancing the activity of cells expressingCD122 and/or γc. In some embodiments, the cells are T cells and/or NKcells.

Accordingly, in a further aspect of the present invention a method isprovided for expanding a population of cells, wherein cells arecontacted in vitro, in vivo or ex vivo with an antibody, antigen bindingfragment, polypeptide or composition according to the present invention.Also provided is a method for expanding a population of cells in asubject, comprising an administering an antibody/fragment an antibody,antigen binding fragment, polypeptide or composition according to thepresent invention to a subject.

In some embodiments, the antibodies/fragments of the present inventionare capable of delivering a survival signal to cells expressing CD122and/or γc. In some embodiments, the antibodies/fragments are useful toenhance/promote the survival of a cell or a population of cells (e.g. Tcells (e.g. CD8+ T cells (e.g. CTLs), CD4+ T cells) and/or NK cells),e.g. in vitro, in vivo or ex vivo.

Accordingly, in a further aspect of the present invention a method isprovided for enhancing/promoting the survival of a cell or a populationof cells, wherein cells are contacted in vitro, in vivo or ex vivo withan antibody, antigen binding fragment, polypeptide or compositionaccording to the present invention. Also provided is a method forenhancing/promoting the survival of a cell or a population of cells in asubject, comprising an administering an antibody/fragment an antibody,antigen binding fragment, polypeptide or composition according to thepresent invention to the subject.

The methods may optionally comprise one or more of the following steps:taking a blood sample from a subject; isolating cells (e.g. one ofPBMCs, T cells, NK cells etc.) from the blood sample; culturing thecells in in vitro or ex vivo cell culture (where they may be contactedwith the antibody, antigen binding fragment or polypeptide), collectingan expanded population of cells; mixing the cells with an adjuvant,diluent, or carrier; administering the expanded cells to a subject.

Accordingly, in some aspects of the present invention a method oftreatment of a subject, e.g. a subject having a T-cell dysfunctionaldisorder, is provided, the method comprising obtaining a blood samplefrom a subject in need of treatment, culturing T cells obtained from theblood sample in the presence of an antibody, antigen binding fragment,polypeptide or composition according to the present invention so as toexpand the T cell population, collecting expanded T cells, andadministering the expanded T cells to a subject in need of treatment.

The T cells may be obtained from a subject requiring treatment, and maybe isolated and/or purified. They may be a CD4⁺ and/or CD8⁺ T-cellpopulation. They may be a CD122⁺ and/or γc+ population.

During culture, T cells may be contacted with the antibody, antigenbinding fragment, polypeptide or composition under conditions and for aperiod of time suitable to allow expansion of the T cells to a desirednumber of cells. After a suitable period of time the T cells may beharvested, optionally concentrated, and may be mixed with a suitablecarrier, adjuvant or diluent and returned to the subject's body. Asubject may undergo one or more rounds of such therapy.

Methods of T cell expansion are well known in the art, such as thosedescribed in Kalamasz et al., J Immunother 2004 September-October;27(5):405-18; Montes et al., Clin Exp Immunol 2005 November;142(2):292-302; Wölfl and Greenburg Nature Protocols 9 p 950-966 27 Mar.2014; Trickett and Kwan Journal of Immunological Methods Vol. 275,Issues 1-2, 1 Apr. 2003, p 251-255; Butler et al PLoSONE 7(1) 12 Jan.2012.

Simultaneous or Sequential Administration

Compositions may be administered alone or in combination with othertreatments, either simultaneously or sequentially dependent upon thecondition to be treated.

In this specification an antibody, antigen binding fragment,polypeptide, CAR, cell or composition of the present invention and ananti-infective agent or chemotherapeutic agent (therapeutic agent) maybe administered simultaneously or sequentially.

In some embodiments, treatment with an antibody, antigen bindingfragment or polypeptide of the present invention may be accompanied bychemotherapy.

Simultaneous administration refers to administration of the antibody,antigen binding fragment or polypeptide and therapeutic agent together,for example as a pharmaceutical composition containing both agents(combined preparation), or immediately after each other and optionallyvia the same route of administration, e.g. to the same artery, vein orother blood vessel.

Sequential administration refers to administration of one of theantibody, antigen binding fragment or polypeptide or therapeutic agentfollowed after a given time interval by separate administration of theother agent. It is not required that the two agents are administered bythe same route, although this is the case in some embodiments. The timeinterval may be any time interval.

In some embodiments, the antibody, antigen binding fragment,polypeptide, or composition of the present invention may be administeredto a patient undergoing treatment by adoptive cell transfer. Theadministration may be aimed at stimulating proliferation of theadoptively transferred cells in the patient in vivo.

Anti-Infective Agents

In treating infection, an antibody, antigen binding fragment orpolypeptide of the present invention may be administered in combinationwith an anti-infective agent, as described above. The anti-infectiveagent may be an agent known to have action against the microorganism orvirus responsible for the infection.

Suitable anti-infective agents include antibiotics (such as penicillins,cephalosporins, rifamycins, lipiarmycins, quinolones, sulfonamides,macrolides, lincosamides, tetracyclines, cyclic lipopeptides,glycylcyclines, oxazolidinones, and lipiarmycins), anti-viral agents(such as reverse transcriptase inhibitors, integrase inhibitors,transcription factor inhibitors, antisense and siRNA agents and proteaseinhibitors), anti-fungal agents (such as polyenes, imidiazoles,triazoles, thiazoles, allylamines, and echinocandins) and anti-parasiticagents (such as antinematode agents, anticestode agents, antitrematodeagents, antiamoebic agents and antiprotozoal agents).

Chemotherapy

Chemotherapy and radiotherapy respectively refer to treatment of acancer with a drug or with ionising radiation (e.g. radiotherapy usingX-rays or γ-rays).

The drug may be a chemical entity, e.g. small molecule pharmaceutical,antibiotic, DNA intercalator, protein inhibitor (e.g. kinase inhibitor),or a biological agent, e.g. antibody, antibody fragment, nucleic acid orpeptide aptamer, nucleic acid (e.g. DNA, RNA), peptide, polypeptide, orprotein. The drug may be formulated as a pharmaceutical composition ormedicament. The formulation may comprise one or more drugs (e.g. one ormore active agents) together with one or more pharmaceuticallyacceptable diluents, excipients or carriers.

A treatment may involve administration of more than one drug. A drug maybe administered alone or in combination with other treatments, eithersimultaneously or sequentially dependent upon the condition to betreated. For example, the chemotherapy may be a co-therapy involvingadministration of two drugs, one or more of which may be intended totreat the cancer.

The chemotherapy may be administered by one or more routes ofadministration, e.g. parenteral, intravenous injection, oral,subcutaneous, intradermal or intratumoral.

The chemotherapy may be administered according to a treatment regime.The treatment regime may be a pre-determined timetable, plan, scheme orschedule of chemotherapy administration which may be prepared by aphysician or medical practitioner and may be tailored to suit thepatient requiring treatment.

The treatment regime may indicate one or more of: the type ofchemotherapy to administer to the patient; the dose of each drug orradiation; the time interval between administrations; the length of eachtreatment; the number and nature of any treatment holidays, if any etc.For a co-therapy a single treatment regime may be provided whichindicates how each drug is to be administered.

Chemotherapeutic drugs and biologics may be selected from: alkylatingagents such as cisplatin, carboplatin, mechlorethamine,cyclophosphamide, chlorambucil, ifosfamide; purine or pyrimidineanti-metabolites such as azathiopurine or mercaptopurine; alkaloids andterpenoids, such as vinca alkaloids (e.g. vincristine, vinblastine,vinorelbine, vindesine), podophyllotoxin, etoposide, teniposide, taxanessuch as paclitaxel (Taxol™), docetaxel; topoisomerase inhibitors such asthe type I topoisomerase inhibitors camptothecins irinotecan andtopotecan, or the type II topoisomerase inhibitors amsacrine, etoposide,etoposide phosphate, teniposide; antitumor antibiotics (e.g.anthracyline antibiotics) such as dactinomycin, doxorubicin(Adriamycin™), epirubicin, bleomycin, rapamycin; antibody based agents,such as anti-PD-1 antibodies, anti-PD-L1 antibodies, anti-TIM-3antibodies, anti-CTLA-4, anti-4-1 BB, anti-GITR, anti-CD27, anti-BLTA,anti-OX43, anti-VEGF, anti-TNFα, anti-IL-2, antiGpIIb/IIIa, anti-CD-52,anti-CD20, anti-RSV, anti-HER2/neu(erbB2), anti-TNF receptor, anti-EGFRantibodies, monoclonal antibodies or antibody fragments, examplesinclude: cetuximab, panitumumab, infliximab, basiliximab, bevacizumab(Avastin®), abciximab, daclizumab, gemtuzumab, alemtuzumab, rituximab(Mabthera®), palivizumab, trastuzumab, etanercept, adalimumab,nimotuzumab; EGFR inhibitors such as erlotinib, cetuximab and gefitinib;anti-angiogenic agents such as bevacizumab (Avastin®); cancer vaccinessuch as Sipuleucel-T (Provenge®).

In one embodiment the chemotherapeutic agent is an anti-PD-1 antibody,anti-PD-L1 antibody, anti-TIM-3 antibody, anti-LAG-3, anti-CTLA-4,anti-41 BB, anti-GITR, anti-CD27, anti-BLTA, anti-OX43, anti-VEGF,anti-TNFα, anti-IL2, anti-GpIIb/IIIa, anti-CD-52, anti-CD20, anti-RSV,anti-HER2/neu(erbB2), anti-TNF receptor, anti-EGFR or other antibody. Insome embodiments, the chemotherapeutic agent is an immune checkpointinhibitor or costimulation molecule.

Further chemotherapeutic drugs may be selected from: 13-cis-RetinoicAcid, 2-Chlorodeoxyadenosine, 5-Azacitidine 5-Fluorouracil,6-Mercaptopurine, 6-Thioguanine, Abraxane, Accutane®, Actinomycin-DAdriamycin®, Adrucil®, Afinitor®, Agrylin®, Ala-Cort®, Aldesleukin,Alemtuzumab, ALIMTA, Alitretinoin, Alkaban-AQ®, Alkeran®,All-transretinoic Acid, Alpha Interferon, Altretamine, Amethopterin,Amifostine, Aminoglutethimide, Anagrelide, Anandron®, Anastrozole,Arabinosylcytosine, Aranesp®, Aredia®, Arimidex®, Aromasin®, Arranon®,Arsenic Trioxide, Asparaginase, ATRA Avastin®, Azacitidine, BCG, BCNU,Bendamustine, Bevacizumab, Bexarotene, BEXXAR®, Bicalutamide, BiCNU,Blenoxane®, Bleomycin, Bortezomib, Busulfan, Busulfex®, CalciumLeucovorin, Campath®, Camptosar®, Camptothecin-11, Capecitabine, Carac™,Carboplatin, Carmustine, Casodex®, CC-5013, CCI-779, CCNU, CDDP, CeeNU,Cerubidine®, Cetuximab, Chlorambucil, Cisplatin, Citrovorum Factor,Cladribine, Cortisone, Cosmegen®, CPT-11, Cyclophosphamide, Cytadren®,Cytarabine Cytosar-U®, Cytoxan®, Dacogen, Dactinomycin, DarbepoetinAlfa, Dasatinib, Daunomycin, Daunorubicin, Daunorubicin Hydrochloride,Daunorubicin Liposomal, DaunoXome®, Decadron, Decitabine, Delta-Cortef®,Deltasone®, Denileukin, Diftitox, DepoCyt™, Dexamethasone, DexamethasoneAcetate, Dexamethasone Sodium Phosphate, Dexasone, Dexrazoxane, DHAD,DIC, Diodex, Docetaxel, Doxil®, Doxorubicin, Doxorubicin Liposomal,Droxia™, DTIC, DTIC-Dome®, Duralone®, Eligard™, Ellence™, Eloxatin™,Elspar®, Emcyt®, Epirubicin, Epoetin Alfa, Erbitux, Erlotinib, ErwiniaL-asparaginase, Estramustine, Ethyol Etopophos®, Etoposide, EtoposidePhosphate, Eulexin®, Everolimus, Evista®, Exemestane, Faslodex®,Femara®, Filgrastim, Floxuridine, Fludara®, Fludarabine, Fluoroplex®,Fluorouracil, Fluoxymesterone, Flutamide, Folinic Acid, FUDR®,Fulvestrant, Gefitinib, Gemcitabine, Gemtuzumab ozogamicin, Gleevec™,Gliadel® Wafer, Goserelin, Granulocyte-Colony Stimulating Factor,Granulocyte Macrophage Colony Stimulating Factor, Herceptin®, Hexadrol,Hexalen®, Hexamethylmelamine, HMM, Hycamtin®, Hydrea®, HydrocortAcetate®, Hydrocortisone, Hydrocortisone Sodium Phosphate,Hydrocortisone Sodium Succinate, Hydrocortone Phosphate, Hydroxyurea,Ibritumomab, Ibritumomab Tiuxetan, Idamycin®, Idarubicin, Ifex®,IFN-alpha, Ifosfamide, IL-11, IL-2, Imatinib mesylate, ImidazoleCarboxamide, Interferon alfa, Interferon Alfa-2b (PEG Conjugate),Interleukin-2, Interleukin-11, Intron A® (interferon alfa-2b), Iressa®,Irinotecan, Isotretinoin, Ixabepilone, Ixempra™, Kidrolase, Lanacort®,Lapatinib, L-asparaginase, LCR, Lenalidomide, Letrozole, Leucovorin,Leukeran, Leukine™, Leuprolide, Leurocristine, Leustatin™, LiposomalAra-C, Liquid Pred®, Lomustine, L-PAM, L-Sarcolysin, Lupron®, LupronDepot®, Matulane®, Maxidex, Mechlorethamine, MechlorethamineHydrochloride, Medralone®, Medrol®, Megace®, Megestrol, MegestrolAcetate, Melphalan, Mercaptopurine, Mesna, Mesnex™, Methotrexate,Methotrexate Sodium, Methylprednisolone, Meticorten®, Mitomycin,Mitomycin-C, Mitoxantrone, M-Prednisol®, MTC, MTX, Mustargen®, Mustine,Mutamycin®, Myleran®, Mylocel™, Mylotarg®, Navelbine®, Nelarabine,Neosar®, Neulasta™, Neumega®, Neupogen®, Nexavar®, Nilandron®,Nilutamide, Nipent®, Nitrogen Mustard, Novaldex®, Novantrone®,Octreotide, Octreotide acetate, Oncospar®, Oncovin®, Ontak®, Onxal™,Oprevelkin, Orapred®, Orasone®, Oxaliplatin, Paclitaxel, PaclitaxelProtein-bound, Pamidronate, Panitumumab, Panretin®, Paraplatin®,Pediapred®, PEG Interferon, Pegaspargase, Pegfilgrastim, PEG-INTRON™,PEG-L-asparaginase, PEMETREXED, Pentostatin, Phenylalanine Mustard,Platinol®, Platinol-AQ®, Prednisolone, Prednisone, Prelone®,Procarbazine, PROCRIT®, Proleukin®, Prolifeprospan 20 with CarmustineImplant Purinethol®, Raloxifene, Revlimid®, Rheumatrex®, Rituxan®,Rituximab, Roferon-A® (Interferon Alfa-2a), Rubex®, Rubidomycinhydrochloride, Sandostatin® Sandostatin LAR®, Sargramostim,Solu-Cortef®, Solu-Medrol®, Sorafenib, SPRYCEL™, STI-571, Streptozocin,SU11248, Sunitinib, Sutent®, Tamoxifen, Tarceva®, Targretin®, Taxol®,Taxotere®, Temodar®, Temozolomide, Temsirolimus, Teniposide, TESPA,Thalidomide, Thalomid®, TheraCys®, Thioguanine, Thioguanine Tabloid®,Thiophosphoamide, Thioplex®, Thiotepa, TICE®, Toposar®, Topotecan,Toremifene, Torisel®, Tositumomab, Trastuzumab, Treanda®, Tretinoin,Trexall™, Trisenox®, TSPA, TYKERB®, VCR, Vectibix™, Velban®, Velcade®,VePesid®, Vesanoid®, Viadur™, Vidaza®, Vinblastine, Vinblastine Sulfate,Vincasar Pfs®, Vincristine, Vinorelbine, Vinorelbine tartrate, VLB,VM-26, Vorinostat, VP-16, Vumon®, Xeloda®, Zanosar®, Zevalin™,Zinecard®, Zoladex®, Zoledronic acid, Zolinza, Zometa®.

Routes of Administration

Antibodies, antigen binding fragments, polypeptides and othertherapeutic agents, medicaments and pharmaceutical compositionsaccording to aspects of the present invention may be formulated foradministration by a number of routes, including but not limited to,parenteral, intravenous, intra-arterial, intramuscular, subcutaneous,intradermal, intratumoral and oral. Antibodies, antigen bindingfragments, polypeptides and other therapeutic agents, may be formulatedin fluid or solid form. Fluid formulations may be formulated foradministration by injection to a selected region of the human or animalbody.

Dosage Regime

Multiple doses of the antibody, antigen binding fragment, polypeptide,CAR, cell, or composition of the invention may be provided. One or more,or each, of the doses may be accompanied by simultaneous or sequentialadministration of another therapeutic agent.

Multiple doses may be separated by a predetermined time interval, whichmay be selected to be one of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or31 days, or 1, 2, 3, 4, 5, or 6 months. By way of example, doses may begiven once every 7, 14, 21 or 28 days (plus or minus 3, 2, or 1 days).

The antibody of the present invention has favourable pharmacokinetics ascompared to IL-2 as a therapeutic agent. An advantage of theantibody/fragment of the present invention is the improved half-life invivo, e.g. in the blood or serum, as compared to IL-2, which means thatadministration of the antibody/fragment can be less frequent, and/or ofa lower amount of the agent.

Kits

In some aspects of the present invention a kit of parts is provided. Insome embodiments the kit may have at least one container having apredetermined quantity of the antibody, fragment, polypeptide, CAR, cellor composition. The kit may provide the antibody, fragment, polypeptide,CAR, or cell in the form of a medicament or pharmaceutical composition,and may be provided together with instructions for administration to apatient in order to treat a specified disease or condition. Theantibody, fragment, polypeptide, CAR, cell or composition may beformulated so as to be suitable for injection or infusion to a tumor orto the blood.

In some embodiments the kit may further comprise at least one containerhaving a predetermined quantity of another therapeutic agent (e.g.anti-infective agent or chemotherapy agent). In such embodiments, thekit may also comprise a second medicament or pharmaceutical compositionsuch that the two medicaments or pharmaceutical compositions may beadministered simultaneously or separately such that they provide acombined treatment for the specific disease or condition. Thetherapeutic agent may also be formulated so as to be suitable forinjection or infusion to a tumor or to the blood.

Subjects

The subject to be treated may be any animal or human. The subject ispreferably mammalian, more preferably human. The subject may be anon-human mammal, but is more preferably human. The subject may be maleor female. The subject may be a patient. A subject may have beendiagnosed with a disease or condition requiring treatment, or besuspected of having such a disease or condition.

Protein Expression

Molecular biology techniques suitable for producing the antibody,fragment, polypeptide, or CAR according to the invention in cells arewell known in the art, such as those set out in Sambrook et al.,Molecular Cloning: A Laboratory Manual, New York: Cold Spring HarborPress, 1989

The polypeptide may be expressed from a nucleotide sequence. Thenucleotide sequence may be contained in a vector present in a cell, ormay be incorporated into the genome of the cell.

A “vector” as used herein is an oligonucleotide molecule (DNA or RNA)used as a vehicle to transfer exogenous genetic material into a cell.The vector may be an expression vector for expression of the geneticmaterial in the cell. Such vectors may include a promoter sequenceoperably linked to the nucleotide sequence encoding the gene sequence tobe expressed. A vector may also include a termination codon andexpression enhancers. Any suitable vectors, promoters, enhancers andtermination codons known in the art may be used to express polypeptidesfrom a vector according to the invention. Suitable vectors includeplasmids, binary vectors, viral vectors and artificial chromosomes (e.g.yeast artificial chromosomes).

In this specification the term “operably linked” may include thesituation where a selected nucleotide sequence and regulatory nucleotidesequence (e.g. promoter and/or enhancer) are covalently linked in such away as to place the expression of the nucleotide sequence under theinfluence or control of the regulatory sequence (thereby forming anexpression cassette). Thus a regulatory sequence is operably linked tothe selected nucleotide sequence if the regulatory sequence is capableof effecting transcription of the nucleotide sequence. Whereappropriate, the resulting transcript may then be translated into adesired protein or polypeptide.

Any cell suitable for the expression of polypeptides may be used forproducing peptides according to the invention. The cell may be aprokaryote or eukaryote. Suitable prokaryotic cells include E. coli.Examples of eukaryotic cells include a yeast cell, a plant cell, insectcell or a mammalian cell. In some cases the cell is not a prokaryoticcell because some prokaryotic cells do not allow for the samepost-translational modifications as eukaryotes. In addition, very highexpression levels are possible in eukaryotes and proteins can be easierto purify from eukaryotes using appropriate tags. Specific plasmids mayalso be utilised which enhance secretion of the protein into the media.

Methods of producing a polypeptide of interest may involve culture orfermentation of a cell modified to express the polypeptide. The cultureor fermentation may be performed in a bioreactor provided with anappropriate supply of nutrients, air/oxygen and/or growth factors.Secreted proteins can be collected by partitioning culturemedia/fermentation broth from the cells, extracting the protein content,and separating individual proteins to isolate secreted polypeptide.Culture, fermentation and separation techniques are well known to thoseof skill in the art.

Bioreactors include one or more vessels in which cells may be cultured.Culture in the bioreactor may occur continuously, with a continuous flowof reactants into, and a continuous flow of cultured cells from, thereactor. Alternatively, the culture may occur in batches. The bioreactormonitors and controls environmental conditions such as pH, oxygen, flowrates into and out of, and agitation within the vessel such that optimumconditions are provided for the cells being cultured.

Following culture of cells that express the polypeptide of interest,that polypeptide is preferably isolated. Any suitable method forseparating polypeptides/proteins from cell culture known in the art maybe used. In order to isolate a polypeptide/protein of interest from aculture, it may be necessary to first separate the cultured cells frommedia containing the polypeptide/protein of interest. If thepolypeptide/protein of interest is secreted from the cells, the cellsmay be separated from the culture media that contains the secretedpolypeptide/protein by centrifugation. If the polypeptide/protein ofinterest collects within the cell, it will be necessary to disrupt thecells prior to centrifugation, for example using sonification, rapidfreeze-thaw or osmotic lysis. Centrifugation will produce a pelletcontaining the cultured cells, or cell debris of the cultured cells, anda supernatant containing culture medium and the polypeptide/protein ofinterest.

It may then be desirable to isolate the polypeptide/protein of interestfrom the supernatant or culture medium, which may contain other proteinand non-protein components. A common approach to separatingpolypeptide/protein components from a supernatant or culture medium isby precipitation. Polypeptides/proteins of different solubility areprecipitated at different concentrations of precipitating agent such asammonium sulfate. For example, at low concentrations of precipitatingagent, water soluble proteins are extracted. Thus, by adding increasingconcentrations of precipitating agent, proteins of different solubilitymay be distinguished. Dialysis may be subsequently used to removeammonium sulfate from the separated proteins.

Other methods for distinguishing different polypeptides/proteins areknown in the art, for example ion exchange chromatography and sizechromatography. These may be used as an alternative to precipitation, ormay be performed subsequently to precipitation.

Once the polypeptide/protein of interest has been isolated from cultureit may be necessary to concentrate the protein. A number of methods forconcentrating a protein of interest are known in the art, such asultrafiltration or lyophilisation.

Sequence Identity

Alignment for purposes of determining percent amino acid or nucleotidesequence identity can be achieved in various ways known to a person ofskill in the art, for instance, using publicly available computersoftware such as ClustalW 1.82. T-coffee or Megalign (DNASTAR) software.When using such software, the default parameters, e.g. for gap penaltyand extension penalty, are preferably used. The default parameters ofClustalW 1.82 are: Protein Gap Open Penalty=10.0, Protein Gap ExtensionPenalty=0.2, Protein matrix=Gonnet, Protein/DNA ENDGAP=−1, Protein/DNAGAPDIST=4.

The invention includes the combination of the aspects and preferredfeatures described except where such a combination is clearlyimpermissible or expressly avoided.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described.

Aspects and embodiments of the present invention will now beillustrated, by way of example, with reference to the accompanyingfigures. Further aspects and embodiments will be apparent to thoseskilled in the art. All documents mentioned in this text areincorporated herein by reference.

Throughout this specification, including the claims which follow, unlessthe context requires otherwise, the word “comprise,” and variations suchas “comprises” and “comprising,” will be understood to imply theinclusion of a stated integer or step or group of integers or steps butnot the exclusion of any other integer or step or group of integers orsteps.

It must be noted that, as used in the specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the context clearly dictates otherwise. Ranges may be expressedherein as from “about” one particular value, and/or to “about” anotherparticular value. When such a range is expressed, another embodimentincludes from the one particular value and/or to the other particularvalue. Similarly, when values are expressed as approximations, by theuse of the antecedent “about,” it will be understood that the particularvalue forms another embodiment.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments and experiments illustrating the principles of the inventionwill now be discussed with reference to the accompanying figures, inwhich:

FIG. 1. Light chain variable domain sequences for anti-IL-2Rβ antibodyclones. CDRs are underlined and shown separately.

FIG. 2. Heavy chain variable domain sequences for anti-IL-2Rβ antibodyclones. CDRs are underlined and shown separately.

FIG. 3. Light chain variable domain sequences for anti-γc antibodyclones. CDRs are underlined and shown separately.

FIG. 4. Heavy chain variable domain sequences for anti-γc antibodyclones. CDRs are underlined and shown separately.

FIG. 5. Table showing light chain CDR sequences for anti-IL-2Rβ antibodyclones.

FIG. 6. Table showing heavy chain CDR sequences for anti-IL-2Rβ antibodyclones.

FIG. 7. Table showing light chain CDR sequences for anti-γc antibodyclones.

FIG. 8. Table showing heavy chain CDR sequences for anti-γc antibodyclones.

FIG. 9. Table showing light chain CDR sequences for P2C4-derivedanti-IL-2Rβ antibody clones.

FIG. 10. Table showing heavy chain CDR sequences for P2C4-derivedanti-IL-2Rβ antibody clones.

FIG. 11. Table showing light chain CDR sequences for P1A3-derivedanti-γc antibody clones.

FIG. 12. Table showing heavy chain CDR sequences for P1A3-derivedanti-γc antibody clones.

FIG. 13. CH2 and CH3 domain sequences for anti-IL-2Rβ antibody cloneP2C4.

FIG. 14. CH2 and CH3 domain sequences for anti-γc antibody clone P1A3.

FIG. 15. Amino acid sequences for anti-IL-2Rβ antibody clones. V_(H)domains are shown underlined. (GGGS)₃ linkers (and variants thereof) areshown in bold. V_(L) domains are shown double underlined. Short linkersare in italics and bold. Hinges are shown in italics. CH2 domains areshown dotted underline. CH3 domains are shown dashed underlined.

FIG. 16. Amino acid sequences for anti-γc antibody clones. V_(H) domainsare shown underlined. (GGGS)₃ linkers (and variants thereof) are shownin bold. V_(L) domains are shown double underlined. Short linkers are initalics and bold. Hinges are shown in italics. CH2 domains are showndotted underline. CH3 domains are shown dashed underlined.

FIG. 17. Nucleotide sequences for anti-IL-2R antibody clones.

FIG. 18. Nucleotide sequences for anti-γc antibody clones.

FIG. 19. Schematic representation of the bispecific anti-IL-2Rβ/γcantibody.

FIG. 20. Sensorgrams showing binding of the bispecific anti-IL-2Rβ/γcantibody to (A) human IL-2Rβ and (B) human γc as determined by surfaceplasmon resonance analysis.

FIG. 21. Histograms showing binding of bispecific anti-IL-2Rβ/γcantibody (A) to cells expressing (and control cells not expressing)IL-2Rβ/γc, and (B) to PBMCs, as determined by flow cytometry.

FIG. 22. Histograms showing induction of STAT5, Akt and ERK mediatedsignalling by treatment of NK92 cells with IL-2 or bispecificanti-IL-2Rβ/γc antibody in vitro, as determined by flow cytometry.

FIG. 23. Graph showing percent phosphorylation of STAT5 in response totreatment with IL-2 or bispecific anti-IL-2Rβ/γc antibody in vitro fordifferent immune cell subsets, as determined by flow cytometry.

FIG. 24. Graph showing proliferation of IL-2 dependent NK92 cells inresponse to treatment with bispecific anti-IL-2Rβ/γc antibody or controlantibodies exhibiting specificity for only IL-2Rβ or γc.

FIG. 25. Graphs and schematic showing results of analysis of linkerlength on binding by anti-IL-2Rβ/γc antibody. (A) Schematicrepresentation of antibody and scFv formats, and linkers (linkers shownin italics). (B) Graph showing proliferation of NK92 cells in responseto treatment with bispecific anti-IL-2Rβ/γc antibody comprising linkersof different length. (C) Graph showing proliferation of NK92 cells inresponse to treatment with bispecific anti-IL-2Rβ/γc in bis-scFv format,comprising linkers of different length.

FIG. 26. Histograms showing induction of STAT5 signalling in cynomolgusmacaque splenocytes by treatment with IL-2 or bispecific anti-IL-2Rβ/γcantibody in vitro, as determined by flow cytometry.

FIG. 27. Graphs showing T cell numbers and ratios following culture ofPBMCs for 1 week in the presence of recombinant human IL-2 or theindicated amount of bispecific anti-IL-2Rβ/γc antibody (Mega2). (A) CD3+cells, (B) CD4+ cells, (C) CD8+ cells, and (D) the ratio of CD8+ to CD4+cells.

FIG. 28. Graph showing the percentage of Tregs following culture ofPBMCs for 1 week in the presence of recombinant human IL-2 or theindicated amount of bispecific anti-IL-2Rβ/γc antibody (Mega2).

FIG. 29. Graph showing CD8+ T cell subsets as a percentage of CD8+ cellsfollowing culture of PBMCs for 1 week in the presence of recombinanthuman IL-2 or the indicated amount of bispecific anti-IL-2Rβ/γc antibody(Mega2). For each subset, from left to right, the data points are: IL-2200 ng/ml, Mega2 3 ug/ml, Mega2 1 ug/ml, Mega2 0.3 ug/ml, Mega2 0.3ug/ml and CD3/28.

FIG. 30. Graphs showing T cell numbers and ratios following culture ofPBMCs from a EBV-seropositive donor in the presence of EBV-LCLs andrecombinant human IL-2 or the indicated amount of bispecificanti-IL-2Rβ/γc antibody (Mega2). (A) CD3+ cells, (B) CD4+ cells, (C)CD8+ cells, and (D) the ratio of CD8+ to CD4+ cells.

FIG. 31. Graphs showing T cell subsets following culture of PBMCs from aEBV-seropositive donor in the presence of EBV-LCLs and recombinant humanIL-2 or the indicated amount of bispecific anti-IL-2Rβ/γc antibody(Mega2). (A) CD8+ T cell subsets as a percentage of CD8+ cells. For eachsubset, from left to right, the data points are: IL-2 200 ng/ml, Mega2 3ug/ml, Mega2 1 μg/ml, Mega2 0.3 ug/ml, Mega2 0.3 ug/ml and CD3/28. (B)CD8+PD1+ cells as a percentage of CD8+ cells, and (C) Tregs as apercentage of CD4+ cells.

FIG. 32. Graph showing CTL cytotoxicity following culture of PBMCs froma EBV-seropositive donor in the presence of EBV-LCLs and recombinanthuman IL-2 or the indicated amount of bispecific anti-IL-2Rβ/γc antibody(Mega2).

FIG. 33. Bar charts showing thermostability of P1A3 family clones.Binding of P1A3 and the mutated clones (A) B4 and E9 and (B) B3 and E8to γc before and after heat treatment. Mean±SD on duplicates is shown.

FIG. 34. Bar charts showing thermostability of P2C4 family clones.Binding of P2C4 and the mutated clones (A) A9, B1, B5, B6, B8, C4, C7,C12, E2, E3, E7, E8, E9, G2, G1l, H1, H2, and H3, and (B) A4, B12, C1,D10, E6, F8, F11 and C1D10 to IL2-Rβ before and after heat treatment.Mean±SD on duplicates is shown.

FIG. 35. Graphs showing binding of (A) P2C4_FW2 single chain antibody toIL-2Rβ, and (B) P1A3_FW2 single chain antibody to γc.

FIG. 36. Graphs showing binding of the bispecific antibody cloneP2C4/P1A3 to (A) IL-2Rβ, and (B) γc, for antibodies having the NSGAGTAAA(SEQ ID NO:157) or GGGGSAAA (SEQ ID NO:158) short linkers.

FIG. 37. Graphs showing binding of bispecific engineered antibody clonesto (A) IL-2Rβ, and (B) γc.

FIG. 38. Graphs showing in vitro response of antigen-specific CD8+ Tcells to bispecific anti-IL-2Rβ/γc antibody exposure, as measured byflow cytometry. (A) Bispecific anti-IL-2Rβ/γc antibody-dependentexpansion of CD8+ T cells. (B) CD8:CD4+ T cell ratio following exposureto the antibody relative to IL-2, following autologous LCL co-culture.*p value <0.05.

FIG. 39. Graphs showing in vitro response of Treg cells to bispecificanti-IL-2Rβ/γc antibody exposure, as measured by flow cytometry, in (A)an antigen-specific, or (B) non-specific setting. *p value <0.05.

FIG. 40. Bar charts showing levels of cytokines as measured by Luminexanalysis (A) IFNγ, (B) IL-15, (C) IL-113, (D) IL-6, and (E) TNFα in theplasma of non-human primates, before and after administration ofanti-IL-2Rβ/γc antibody.

FIG. 41. Bar charts showing in vivo response of T cell subsets tobispecific anti-IL-2Rβ/γc antibody injection, as measured by flowcytometry. (A) T cells as a proportion of the total leukocytepopulation, (B) Ki-67+ positive CD8+ cells as a proportion of the totalCD8+ T cell population. (C) Ki-67+ positive CD4+ cells as a proportionof the total CD4+ T cell population. Bispecific antibody dependentexpansion is indicated by the increase in T cells relative to the totalleukocyte population.

FIG. 42. Bar charts showing in vivo response of NK cells to bispecificanti-IL-2Rβ/γc antibody injection, as measured by flow cytometry. (A) NKcells as a proportion of the pre-dose total leukocyte population, (B)Ki-67+ positive NK cells as a proportion of the total NK cellpopulation.

EXAMPLES

In the following Examples, the inventors describe the isolation ofanti-IL-2Rβ and anti-γc antibodies, construction, engineering and invitro and in vivo functional characterisation of bispecificanti-IL-2Rβ/γc antibodies.

Example 1: Isolation of Anti-Human IL-2Rβ and Anti-Human γc Antibodies

Anti-IL-2Rβ and anti-γc antibodies were isolated from a human antibodyphage display library via in vitro selection. Specific Fab antibodieswere originally identified by ELISA using recombinant IL-2Rβ and γcproteins as antigens.

Example 2: Construction of a Bispecific Antibody Targeting the MediumAffinity IL-2Rβ-γc

Clones showing a strong binding in ELISA (Example 1) were selected andused to construct a “knob-in-hole” monovalent, bispecific human antibodybased on a single chain variable fragment (scFv) linked to a IgG1backbone Fc region as schematised in FIG. 19.

The “knob-in-hole” format prevents homodimerisation and formation ofbivalent, monospecific antibodies.

A LALA mutation (substitution of leucine residues 234 and 235 in wildtype heavy chain constant domain 2 by alanine) was introduced in the Fcportion of the antibody to abrogate binding to Fc receptor.

The size of the linker between the scFv domain and the Fc domain has noeffect on the function of the construct (see Example 6.2 and FIG. 25).

Bispecific scFv (Bis-scFv) Format:

P1A3 and P2C4 scFv were tied with a linker to form a bispecific antibodycomposed of two single chain variable domains connected by a linker(FIG. 25A, right). Different linker sizes were tested (FIG. 25C) andactivity was tested by measuring NK92 cell growth.

The bis-scFv was effective in maintaining proliferation of NK92 cells inthe absence of IL-2. The linker size between the two single chainfragments did not affect the bispecific compound activity (FIG. 25C).

Example 3: Analysis of Binding to IL-2R Chains

The binding of the bispecific antibody to either IL-2Rβ or γc wasanalysed by flow cytometry.

Antibodies were incubated with HEK-293.6E cells that had previously beentransfected with constructs encoding either IL-2Rβ or γc.

Binding to the cells was detected using a fluorescent-conjugatedsecondary antibody. An isotype IgG1 was used as a negative control.Bispecific constructs with specificity for either IL-2R or γc and for anirrelevant target were also tested.

The anti-IL-2Rβ/γc antibody was shown to bind to cells expressing itstargets (FIG. 21A).

Example 4: Analysis of Affinity for IL-2R Chains

Association/dissociation of the anti-IL-2Rβ/γc bispecific antibodyto/from the receptor chains was measured in Surface Plasmon Resonanceusing recombinant IL-2Rβ or γc chains immobilised on a chip, and flowingvarious concentrations of the antibody over the surface.

The antibody showed a very high affinity for IL-2Rβ or γc chains, with avery rapid binding and a very slow dissociation (FIG. 20).

Affinity was measured for bispecific anti-IL-2Rβ/γc antibody P2C4/P1A3,and other bispecific antibodies shown in Table 1.

TABLE 1 Bispecific Ab K_(D) (M) anti-IL-2Rβ clone anti-γc clone forIL-2Rβ for γc P2C4 P1A3 1.43 × 10⁻⁷ 2.09 × 10⁻⁸ P2H7 P2B9 1.01 × 10⁻⁷7.98 × 10⁻⁸ P2D12 P1A3 1.81 × 10⁻⁷ 7.87 × 10⁻⁸ P1G11 P1A3 1.28 × 10⁻⁷3.37 × 10⁻⁷

Example 5: Binding to PBMC Subsets

The bispecific IgG anti-IL-2Rβ/γc antibody was tested on PBMCs isolatedfrom healthy donors to check which cell subsets it binds to. Antibody orisotype IgG control were added to PBMCs and detected with afluorescently-conjugated secondary anti-human IgG antibody in flowcytometry assays.

The anti-IL-2Rβ/γc bispecific antibody did not show high binding forCD4+ or CD8+ T cells. However, the antibody bound efficiently to CD56+NKcells, CD19+ B cells and CD14+/CD16+ monocytes (FIG. 21B).

Example 6: Activity/IL-2 Agonistic Effects of Anti-IL-2Rβ/γc BispecificAntibody

6.1 Signalling Pathway Phosphorylation

IL-2 is known to trigger intracellular signalling via STAT5, ERK and Aktpathways. The anti-IL-2Rβ/γc bispecific antibody was tested for itsability to induce signalling through these pathways.

IL-2-sensitive NK92 cells were deprived from serum and then stimulatedeither with IL-2 (100 U/ml, i.e. ˜0.5 nM¹) or the anti-IL-2Rβ3/γcantibody (10 pg/ml, i.e. ˜95 nM²) for 30 minutes, and phosphorylation ofSTAT5, Akt and ERK was detected using fluorescent antibodies in flowcytometry assays.

The anti-IL-2Rβ/γc antibody induced STAT5 and Akt phosphorylation,although in a milder way than IL-2 (FIG. 22). In this assay, theIL-2Rβ/γc antibody did not trigger phosphorylation of ERK (FIG. 22).

One of the biggest obstacles to therapeutic use of IL-2 is thepreferential stimulation of cells expressing the high affinityheterotrimeric receptor CD25, e.g. regulatory T cells (Tregs), activatedT cells, activated B cells, some myeloid precursor cells, and epithelialcells.

Phosphorylation of STAT5 in the presence of IL-2 or anti-IL-2Rβ/γcantibody was measured by flow cytometry in Tregs, CD8+ T cells and NKcells obtained from healthy donors.

Small amounts of IL-2 were sufficient to activate NK or T cells, buteven at low levels of IL-2 Tregs were preferentially and stronglyactivated. At concentrations giving less than 20% activation of theSTAT5 signaling pathway in NK or CD8+ T cells, Tregs already showed 100%activation (FIG. 23).

By contrast, the bispecific antibody showed a different activationprofile with a lower preferential activation of Tregs. At concentrationsresulting in a 20% activation of NK and CD8+ T cells, Tregs showedbetween 39 and 49% STAT5 phosphorylation. At concentrations giving 50%of activation in NK and CD8+ T cells, the Treg population was still notcompletely activated, with 73-78% STAT5 phosphorylation (FIG. 23).

6.2 Proliferation of IL-2-Dependent Cells

Viability and growth of NK92 cells was measured with Alamar blue dye inthe absence of IL-2.

The anti-IL-2Rβ/γc antibody was able to maintain proliferation of NK92cells in the absence of IL-2, whilst the antibody constructs binding toonly one chain of the IL-2 receptor did not show any effect (FIG. 24).

To assess whether the length of the linker had an effect on thefunctionality of the antibody, the same assay was conducted usingantibodies with different linker sizes.

Growth of NK92 cells was not affected by linker size (FIG. 25B). Thedata in FIG. 25B were obtained using the shortest and the longestlinkers (between 5 and 23 amino-acids).

Linkers of different length were analysed in the bispecific antibodyformat, or bispecific scFv format, as represented schematically in FIG.25A. Briefly, P1A3 and P2C4 scFv were linked with linkers of differentsize, and the activity was tested by measuring NK92 cell growth.

The results are shown in FIGS. 25B and 25C. The bis-scFv is effective inmaintaining proliferation of NK92 cells in the absence of IL-2, and thesize of the linker between the two scFv fragments does not affectactivity.

6.3 Cross-Reactivity with Cynomolgus Monkey Cells

The anti-IL-2Rβ/γc antibody was also tested on Non-Human Primate cells.Briefly, Cynomolgus splenocytes were incubated in the presence of humanIL-2 or the bispecific antibody and STAT5 phosphorylation was measured.The antibody was found to be cross-reactive with Cynomolgus IL-2R, andtriggered phosphorylation of STAT5 as efficiently as human IL-2 (FIG.26).

6.4 Conclusion

Taken together, these data show that the anti-IL-2Rβ/γc bispecificantibody has some agonist effects to IL-2, and that these effects arenot highly preferentially directed towards CD25-expressing cells.

Example 7: Modulation of the Immune Response: Control of T CellExpansion in a Non-Specific Stimulation Setting

Peripheral blood mononuclear cells (PBMCs) were isolated from avolunteer donor and cultured for 1 week in the presence of recombinanthuman IL-2 (200 ng/ml), the anti-IL-2Rβ/γc bispecific antibody (3, 1,0.3, 0.1, or 0.03 μg/ml) or anti-CD3/CD28 beads as a positive control.After 1 week, cell expansion was assessed by measuring absolute cellcounts; cell subset proportions were measured by FACS.

7.1 Expansion of T Cells

At comparable concentrations (IL-2 200 ng/ml≈12 nM; Bispecificanti-IL-2Rβ/γc antibody 3 μg/ml≈20 nM), the antibody triggers T cellproliferation to a lesser extent than IL-2 (FIG. 27A to 27C). Thebispecific antibody shows a dose-dependent effect on T cellproliferation (FIG. 27A to 27D). In a non-specific stimulation setting,the CD8:CD4 cell ratio was not significantly different in the presenceof the anti-IL-2Rβ/γc antibody as compared to when cells were culturedwith IL-2 (FIG. 27D).

7.2 Stimulation of Regulatory T Cells

Regulatory T cells (Tregs) express the high affinity IL-2 receptorsub-chain IL-2Rα. In a non-specific stimulation setting, IL-2preferentially stimulates regulatory T cells amongst CD3+CD4+ T cells;such Treg expansion was not triggered by the bispecific anti-IL-2Rβ/γcantibody (FIG. 28).

7.3 Stimulation of Effector Vs Memory Cells

With respect to memory CD8+ lymphocytes, the bispecific anti-IL-2Rβ/γcantibody triggers greater expansion of the effector memory CD8+ T cellsubset, whilst triggering less expansion of the central memory and naïveCD8+ T cell subsets as compared to expansion in response to stimulationwith IL-2 (FIG. 29).

Example 8: Modulation of the Immune Response: Control of T CellExpansion in a Specific Stimulation Setting

PBMCs from an Epstein-Barr virus (EBV) seropositive volunteer donor wereinfected with EBV to make lymphoblastoid cell lines (LCLs). LCLs weresorted and γ-irradiated in order to inhibit their subsequentproliferation. Irradiated LCLs were co-cultured at a density of 1×10⁵cells/ml with 2×10⁶ autologous PBMCs/ml for 2 weeks, in the presence ofIL-2, the anti-IL-2Rβ/γc bispecific antibody or anti-CD3/CD28 beads(positive control). Cells were then analysed for proliferation and theproportions of different cell subsets.

A cytotoxic killing assay was performed using a fluorescent peptidesubstrate for granzyme B and capsase 8. Expanded T-cells wereco-incubated with live LCLs at a ratio of 2:1 for one hour. Killing wasmeasured by analysis of peptide-fluorescent positive cells by flowcytometry, which indicated that cells were undergoing CTL-inducedprogrammed cell death.

8.1 Expansion of T Cells

The bispecific antibody triggers expansion of T cells, even at lowconcentrations. Anti-IL-2Rβ3/γc bispecific antibody-mediated T cellexpansion is slightly greater than expansion observed followingstimulation with IL-2 (FIG. 30A). Whilst the antibody does notsignificantly influence the number of CD4+ T cells (FIG. 30B), theantibody elicits an increase in the number of CD8+ T cells to a greaterextent than IL-2 (FIG. 30C), and hence increased the CD8:CD4 cell ratio(FIG. 30D).

8.2 Effects on T Cell Subsets

At the highest concentration (1 μg/ml), the anti-IL-2Rβ/γc antibodyfavours the expansion of effector CD8+ T cells over CD8+ memory cells ascompared to stimulation with IL-2 (FIG. 31A). Compared to IL-2stimulation, the anti-IL-2Rβ/γc antibody also triggers an increase inthe CD8+PD-1+ subset (FIG. 31B), whilst decreasing the proportion ofTregs (FIG. 31C).

8.3 Cytotoxic T Lymphocyte-Mediated Killing

The anti-IL-2Rβ/γc bispecific antibody is able to elicit CTLcytotoxicity. At comparable molarity (12 nM (200 ng/ml) for IL-2 vs. 7nM (1 μg/mL) for the antibody), the antibody-mediated cytotoxicity islower than cytotoxicity triggered by IL-2 (FIG. 32).

8.4 Conclusion

Taken together, the data suggest that the bispecific anti-IL-2Rβ/γcantibody triggers a different mechanism of action than that of IL-2. Theantibody preferentially elicits expansion of effector CD8+ T cells. Theantibody allows stimulation of cytotoxic T cells but does notpreferentially stimulate Tregs as IL-2 does.

Example 9: Sequence Engineering to Improve Stability

One of the greatest challenges whilst constructing bispecific antibodiesis the stability of the heterogenic construct. Unlike monospecific IgGs,the present bispecific anti-IL-2Rβ/γc antibody is an artificialassembling of two different pairs of light/heavy chains.

In order to improve the general stability of constructs, originalantibody clones P2C4 and P1A3 were engineered to increase theirthermostability.

9.1 Thermostable Clones

Libraries of randomly mutagenised clones were built from the parentclones P2C4 and P1A3 and mutants were screened for binding to therespective targets in a two-round panning followed by ELISA. Binderswere then subjected to heating to 55° C. The mutants still binding afterheating were sequenced, and unique clones were identified.

Thermostability of the clones was assessed after heating for 4 hoursbetween 45° C. and 65° C., by measuring binding to their respectivetarget, either γc (FIGS. 33A and 33B) or IL-2Rβ (FIGS. 34A and 34B), inELISA. The mutated clones showed higher thermal stability than theparent clones.

9.1 Engraftment of Highly Stable Framework

In order to further increase stability of the antibody, clones wereengrafted in frameworks of antibodies that were known to be highlystable.

P2C4 and P1A3 were engrafted into frameworks of antibodies known to havehigh stability. ELISA experiments were conducted to ensure that the newclones retained the ability to bind to IL-2Rβ and γc.

Both P2C4_FW2 and P1A3_FW2 showed a dose-dependent binding profile toIL-2Rβ and γc respectively (FIGS. 35A and 35B).

Example 10: Binding of New Bispecific Constructs to IL-2Rβ/γc

10.1 Short Linker Between Variable and Constant Domains

Bispecific antibody constructs were prepared including one of thefollowing short linkers between the scFv and constant domain (antibodyformat: VH domain-linker-VL domain-short linker-hinge-CH2 domain(+LALA)-CH3 domain (+knob/hole+cys)): NSGAGTAAA (SEQ ID NO: 157) orGGGGSAAA (SEQ ID NO: 158).

Bispecific constructs with NSGAGTAAA (SEQ ID NO:157) or GGGGSAAA (SEQ IDNO:158) short linkers were generated and tested for binding to IL-2Rβand γc by ELISA.

The bispecific antibodies were found to bind to with similar affinityirrespective of the identity of the short linker (FIGS. 36A and 36B).

Bispecific antibodies were constructed with the new sequences andbinding was assessed by ELISA on either IL-2Rβ or IL-2Rγc. Theconstructs were found to bind similar or better affinity than the parentbispecific antibodies to IL-2R (FIGS. 37A and 37B).

Example 11: Effects on T Cell Expansion and Polarisation

Assays using T cells were performed in order to measure the effect ofthe anti-IL-2Rβ/γc bispecific antibody on T cell expansion in vitro andits impact on antigen specific and non-specific qualitative polarisationand subset specificity. Peripheral blood from EBV-positive individualswas used to generate both EBV-transformed lymphoblastoid B-cell lines(LCLs) and EBV-specific CTL lines.

Briefly, to generate LCLs, PBMCs were cultured for 1 week in thepresence of cyclosporine and EBV, and for 2 additional weeks inrefreshed media with cyclosporine but without EBV. After culture, cellswere transferred to a G-Rex column and growth was monitored. For thegeneration of CTLs, LCLs were irradiated to act as an antigen source forCTLs. PBMCs were co-cultured with LCLs at an effector to stimulator(E:S) ratio of 40:1. Cells were stimulated by addition of IL-2, theanti-IL-2Rβ/γc bispecific antibody, or CD3/28 beads.

After 7 days, cells underwent a media change and additionalstimulations. At day 10, cells were analysed for lymphocyte expansionand phenotype by flow cytometry.

Addition of the bispecific antibody was found to result in a significantincrease in antigen-specific CD8+ T cell expansion as compared toexpansion in response to stimulation with IL-2 (FIG. 38A). Furthermore,in vitro cultures showed improved CD8:CD4 ratios following antibodystimulation (FIG. 38B).

The impact of the bispecific antibody on the expansion of regulatory Tcells (Tregs) was then measured and compared to expansion of Tregs inresponse to stimulation with IL-2, in the antigen specific (autologousLCL co-culture) and non-specific (anti-CD3/CD28 microbead) settings.Addition of the bispecific antibody results in significantly reducedexpansion of Tregs as compared to Treg expansion in response to IL-2, inboth the non-specific (FIG. 39A) and antigen-specific stimulationsettings (FIG. 39B).

Example 12: In Vivo Data in Non-Human Primates

A dose escalating experiment was established in Cynomolgus macaques inorder to measure the effects of intravenous (iv) injection of theanti-IL-2Rβ/γc bispecific antibody, its ability to drive proliferationof T cells and NK cells, and its potential toxicity through “cytokinestorm”.

Three macaques were administered a single dose of the anti-IL-2Rβ/γcantibody, intravenously through the femoral artery; macaque A received 1mg/kg, macaque B received 5 mg/kg, and macaque C received 10 mg/kg.Blood was collected before antibody injection and at 1 h, 24 h, 72 h and120 h post-injection.

Vital signs and physical examinations were performed throughout thestudy and then for a further 3 weeks. PBMCs were isolated at all timepoints, leukocyte subsets were analysed by immune-staining and flowcytometry, and cell expansion was assessed by analysis of Ki-67expression. Plasma cytokine levels were measured by Luminex® at all timepoints.

Veterinary physical examination indicated no abnormalities in generalappearance, mucosal membranes, cardiovascular, respiratory,integumentary, alimentary, musculoskeletal, nervous, urogenital,auditory, or ocular systems. Animals displayed no clinical findings offebrile illness or depression. One animal (macaque B) showed mild weightloss from which he recovered during the course of the study. Animalsshowed no overt signs of toxicity commonly associated with IL-2administration (PMID: 1418698 and 8454416).

Consistent with these observations, cytokine analysis demonstrated onlymild increases in inflammatory mediators post injection (FIGS. 40A to40E). Flow cytometric analysis indicated a marked proliferation of CD4+and CD8+ T cell populations (FIGS. 41A to 41C).

NK cell proliferation was also observed in response to the antibodytreatment (FIGS. 42A and 42B). It should be noted that this expansionwas observed after a single dose of antibody, compared to continuousinfusion or repeated doses required for IL-2, suggesting thatanti-IL-2Rβ/γc bispecific antibody has a longer half-life than IL-2.

The invention claimed is:
 1. A method for expanding a population ofcells expressing an IL-2 receptor comprising a complex of CD122 andcommon γ chain (γc), comprising contacting cells expressing the IL-2receptor with an antibody or antigen binding fragment which is an IL-2receptor agonist, and comprises: (a) an antigen-binding fragment whichbinds to CD122, comprising: (i) a light chain variable region comprisingthe following CDRs: LC-CDR1: (SEQ ID NO: 2) TGTSSDIGHYDFVS, LC-CDR2:(SEQ ID NO: 3) DINNRPS, and LC-CDR3: (SEQ ID NO: 4) SAYTSSDTLV;

and (ii) a heavy chain variable region comprising the following CDRs:HC-CDR1: (SEQ ID NO: 36) NYYMH, HC-CDR2: (SEQ ID NO: 37)AIMPSRGGTSYPQKFQG, and HC-CDR3: (SEQ ID NO: 38) GEYYYDSSGYYY;

and (b) an antigen-binding fragment which binds to γc, comprising: (i) alight chain variable region comprising the following CDRs: LC-CDR1:(SEQ ID NO: 68) RSSQSLLHSNGYNYLD, LC-CDR2: (SEQ ID NO: 69) LGSNRDS, andLC-CDR3: (SEQ ID NO: 70) MQGTHWPWT;

and (ii) a heavy chain variable region comprising the following CDRs:HC-CDR1: (SEQ ID NO: 48) GYYWS, HC-CDR2: (SEQ ID NO: 49)EINHSGSTNYNPSLKS, and HC-CDR3: (SEQ ID NO: 77) SPGGYSGGYFQH.


2. The method according to claim 1, wherein the method comprises:culturing cells expressing the IL-2 receptor in the presence of the IL-2receptor agonist antibody or antigen binding fragment to expand thepopulation of cells expressing the IL-2 receptor; and collecting theexpanded population of cells.
 3. The method according to claim 2,wherein the method further comprises: mixing the expanded population ofcells with a pharmaceutically acceptable carrier, adjuvant, excipient ordiluent.
 4. The method according to claim 1, wherein the cellsexpressing the IL-2 receptor comprising a complex of CD122 and γc areobtained from a blood sample from a subject.
 5. The method according toclaim 1, wherein the cells expressing the IL-2 receptor are T cellsand/or NK cells.
 6. The method according to claim 1, wherein the cellsare contacted with the IL-2 receptor agonist antibody or antigen bindingfragment in vitro or ex vivo.
 7. The method according to claim 1,wherein the IL-2 receptor agonist antibody or antigen binding fragmentis provided in scFv-KiH-Fc or CrossMab format.